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\[ \text { If } 8 \sin x=4+\cos x \text {, the values of } \sin x \text { are: } \]
To find the values of \(\sin x\) given the equation \(8\sin x = 4 + \cos x\), we can use trigonometric identities to rewrite the equation in terms of a single trigonometric function. The given equation is: \[8\sin x = 4 + \cos x\] We know the Pythagorean identity: \(\sin^2 x + \cos^2 x = 1\). Our goRead more
To find the values of \(\sin x\) given the equation \(8\sin x = 4 + \cos x\), we can use trigonometric identities to rewrite the equation in terms of a single trigonometric function.
The given equation is:
\[8\sin x = 4 + \cos x\]
We know the Pythagorean identity: \(\sin^2 x + \cos^2 x = 1\). Our goal is to express \(\cos x\) in terms of \(\sin x\) (or vice versa) to solve for \(\sin x\). Since the equation involves both \(\sin x\) and \(\cos x\), and we’re looking to find \(\sin x\), let’s isolate \(\cos x\) and then use the Pythagorean identity.
Rearrange the given equation to isolate \(\cos x\):
\[\cos x = 8\sin x – 4\]
Using the Pythagorean identity \(\cos^2 x = 1 – \sin^2 x\), we substitute for \(\cos x\) in the equation:
\[1 – \sin^2 x = (8\sin x – 4)^2\]
Expanding the right side and moving all terms to one side gives us a quadratic equation in \(\sin x\):
\[1 – \sin^2 x = 64\sin^2 x – 64\sin x + 16\]
Combine like terms:
\[65\sin^2 x – 64\sin x + 15 = 0\]
This is a quadratic equation in \(\sin x\). To solve for \(\sin x\), we use the quadratic formula where \(a = 65\), \(b = -64\), and \(c = 15\):
\[\sin x = \frac{-b \pm \sqrt{b^2 – 4ac}}{2a}\]
\[= \frac{64 \pm \sqrt{(-64)^2 – 4 \cdot 65 \cdot 15}}{2 \cdot 65}\]
\[= \frac{64 \pm \sqrt{4096 – 3900}}{130}\]
\[= \frac{64 \pm \sqrt{196}}{130}\]
\[= \frac{64 \pm 14}{130}\]
So, we have two possible solutions for \(\sin x\):
1. \(\sin x = \frac{64 + 14}{130} = \frac{78}{130} = \frac{39}{65} = \frac{3}{5}\)
2. \(\sin x = \frac{64 – 14}{130} = \frac{50}{130} = \frac{25}{65} = \frac{5}{13}\)
Therefore, the values of \(\sin x\) that satisfy the given equation are \(\frac{3}{5}\) and \(\frac{5}{13}\).
See lessIn covering a distance of 30 km Amit takes 2 hours more than Suresh, If Amit doubles his speed, he would take 1 hour less than Suresh. Amit’s speed is :
- Distance covered by both Amit and Suresh is 30 km. - Amit takes 2 hours more than Suresh to cover this distance. - If Amit doubles his speed, he takes 1 hour less than Suresh. Let's denote: - Amit's original speed as \(s\) km/h. - Suresh's time to cover 30 km as \(t\) hours. From the first conditiRead more
– Distance covered by both Amit and Suresh is 30 km.
– Amit takes 2 hours more than Suresh to cover this distance.
– If Amit doubles his speed, he takes 1 hour less than Suresh.
Let’s denote:
– Amit’s original speed as \(s\) km/h.
– Suresh’s time to cover 30 km as \(t\) hours.
From the first condition, Amit’s time to cover 30 km is \(t + 2\) hours, so we can write Amit’s speed as:
\[ s = \frac{30}{t + 2} \]
From the second condition, if Amit doubles his speed, his time to cover 30 km becomes \(t – 1\) hours. So, we can write:
\[ 2s = \frac{30}{t – 1} \]
Substituting the expression for \(s\) from the first equation into the second equation:
\[ 2 \times \frac{30}{t + 2} = \frac{30}{t – 1} \]
Cross-multiplying:
\[ 60(t – 1) = 30(t + 2) \]
Expanding:
\[ 60t – 60 = 30t + 60 \]
Rearranging:
\[ 30t = 120 \]
\[ t = 4 \text{ hours} \]
Now, we can find Amit’s original speed:
\[ s = \frac{30}{t + 2} = \frac{30}{4 + 2} = \frac{30}{6} = 5 \text{ km/h} \]
So, Amit’s original speed is 5 km/h.
See less If 8sinx=4+cosx, the values of sinx are: \text { If } 8 \sin x=4+\cos x \text {, the values of } \sin x \text { are: }
To find the values of \(\sin x\) given the equation \(8\sin x = 4 + \cos x\), we can use trigonometric identities to rewrite the equation in terms of a single trigonometric function. The given equation is: \[8\sin x = 4 + \cos x\] We know the Pythagorean identity: \(\sin^2 x + \cos^2 x = 1\). Our goRead more
To find the values of \(\sin x\) given the equation \(8\sin x = 4 + \cos x\), we can use trigonometric identities to rewrite the equation in terms of a single trigonometric function.
The given equation is:
\[8\sin x = 4 + \cos x\]
We know the Pythagorean identity: \(\sin^2 x + \cos^2 x = 1\). Our goal is to express \(\cos x\) in terms of \(\sin x\) (or vice versa) to solve for \(\sin x\). Since the equation involves both \(\sin x\) and \(\cos x\), and we’re looking to find \(\sin x\), let’s isolate \(\cos x\) and then use the Pythagorean identity.
Rearrange the given equation to isolate \(\cos x\):
\[\cos x = 8\sin x – 4\]
Using the Pythagorean identity \(\cos^2 x = 1 – \sin^2 x\), we substitute for \(\cos x\) in the equation:
\[1 – \sin^2 x = (8\sin x – 4)^2\]
Expanding the right side and moving all terms to one side gives us a quadratic equation in \(\sin x\):
\[1 – \sin^2 x = 64\sin^2 x – 64\sin x + 16\]
Combine like terms:
\[65\sin^2 x – 64\sin x + 15 = 0\]
This is a quadratic equation in \(\sin x\). To solve for \(\sin x\), we use the quadratic formula where \(a = 65\), \(b = -64\), and \(c = 15\):
\[\sin x = \frac{-b \pm \sqrt{b^2 – 4ac}}{2a}\]
\[= \frac{64 \pm \sqrt{(-64)^2 – 4 \cdot 65 \cdot 15}}{2 \cdot 65}\]
\[= \frac{64 \pm \sqrt{4096 – 3900}}{130}\]
\[= \frac{64 \pm \sqrt{196}}{130}\]
\[= \frac{64 \pm 14}{130}\]
So, we have two possible solutions for \(\sin x\):
1. \(\sin x = \frac{64 + 14}{130} = \frac{78}{130} = \frac{39}{65}\)= \frac{3}{5}\)
2. \(\sin x = \frac{64 – 14}{130} = \frac{50}{130} = \frac{25}{65} = \frac{5}{13}\)
Therefore, the values of \(\sin x\) that satisfy the given equation are \(\frac{3}{5}\) and \(\frac{5}{13}\).
See lessOne of the angles of a triangle is two-third of the sum of the adjacent angles of a parallelogram. The remaining angles of the triangle are in the ratio of 5 : 7. What is the value of the second largest angle of the triangle?
Let's denote the angles of the triangle as \(A\), \(B\), and \(C\), where \(A\) is the angle that is two-third of the sum of the adjacent angles of a parallelogram, and \(B\) and \(C\) are the remaining angles of the triangle in the ratio of 5:7. Since the sum of the angles in a triangle is \(180^\cRead more
Let’s denote the angles of the triangle as \(A\), \(B\), and \(C\), where \(A\) is the angle that is two-third of the sum of the adjacent angles of a parallelogram, and \(B\) and \(C\) are the remaining angles of the triangle in the ratio of 5:7.
Since the sum of the angles in a triangle is \(180^\circ\), we can write:
\[ A + B + C = 180^\circ \]
Given that \(A\) is two-third of the sum of the adjacent angles of a parallelogram, and we know that the sum of the adjacent angles of a parallelogram is \(180^\circ\), we have:
\[ A = \frac{2}{3} \times 180^\circ = 120^\circ \]
Now, given that \(B\) and \(C\) are in the ratio of 5:7, we can write:
\[ B = 5x \]
\[ C = 7x \]
Since the sum of the angles in the triangle is \(180^\circ\), we have:
\[ 120^\circ + 5x + 7x = 180^\circ \]
\[ 12x = 60^\circ \]
\[ x = 5^\circ \]
Now, we can find the values of \(B\) and \(C\):
\[ B = 5x = 5 \times 5^\circ = 25^\circ \]
\[ C = 7x = 7 \times 5^\circ = 35^\circ \]
So, the second largest angle of the triangle is \(35^\circ\).
See less If x=2 then the value of x3+27×2+243x+631 is: \text { If } x=2 \text { then the value of } x^3+27 x^2+243 x+631 \text { is: }
To find the value of the expression \(x^3 + 27x^2 + 243x + 631\) when \(x = 2\), we can substitute the value of \(x\) into the expression and simplify: \[ \begin{aligned} x^3 + 27x^2 + 243x + 631 &= 2^3 + 27(2)^2 + 243(2) + 631 \\ &= 8 + 27(4) + 486 + 631 \\ &= 8 + 108 + 486 + 631 \\Read more
To find the value of the expression \(x^3 + 27x^2 + 243x + 631\) when \(x = 2\), we can substitute the value of \(x\) into the expression and simplify:
\[
\begin{aligned}
x^3 + 27x^2 + 243x + 631 &= 2^3 + 27(2)^2 + 243(2) + 631 \\
&= 8 + 27(4) + 486 + 631 \\
&= 8 + 108 + 486 + 631 \\
&= 1233
\end{aligned}
\]
So, the value of the expression when \(x = 2\) is \(1233\).
See lessSindbad rows 24 km against the flow of water and 54 km with the flow of water in 6 hours. He can also row 36 km against the flow and 48 km with the flow in 8 hours. What is his speed in still water?
Understanding the Problem We are given the rowing speeds of Sindbad in two different scenarios: 1. He rows 24 km upstream and 54 km downstream in 6 hours. 2. He rows 36 km upstream and 48 km downstream in 8 hours. We need to find Sindbad's speed in still water. Let's denote: - Sindbad's speed upstreRead more
Understanding the Problem
We are given the rowing speeds of Sindbad in two different scenarios:
1. He rows 24 km upstream and 54 km downstream in 6 hours.
2. He rows 36 km upstream and 48 km downstream in 8 hours.
We need to find Sindbad’s speed in still water.
Let’s denote:
– Sindbad’s speed upstream as \(x\) km/h.
– Sindbad’s speed downstream as \(y\) km/h.
Solving the Problem
From the given scenarios, we can write two equations:
1. For the first scenario:
\[ \frac{24}{x} + \frac{54}{y} = 6 \]
Simplifying, we get:
\[ \frac{4}{x} + \frac{9}{y} = 1 \text{ —- Eqn(1)} \]
2. For the second scenario:
\[ \frac{36}{x} + \frac{48}{y} = 8 \]
Simplifying, we get:
\[ \frac{9}{x} + \frac{12}{y} = 2 \text{ —- Eqn(2)} \]
Solving equations (1) and (2), we find:
\[ x = \frac{11}{2} \text{ km/h} \text{ (Sindbad’s speed upstream)} \]
\[ y = 33 \text{ km/h} \text{ (Sindbad’s speed downstream)} \]
Sindbad’s speed in still water is the average of his speeds upstream and downstream:
\[ \text{Speed in still water} = \frac{x + y}{2} = \frac{\frac{11}{2} + 33}{2} = \frac{77}{4} = 19.25 \text{ km/h} \]
Conclusion
Sindbad’s speed in still water is 19.25 km/h.
See lessA Shopkeeper has 660 Kesar Petha and 510 Paan Petha. He wants to arrange them in such a manner that each stack has the same number, and they take the least area of the tray. What is the number of Pethas that can be place in each stack for this purpose?
Understanding the Problem The shopkeeper has 660 Kesar Petha and 510 Paan Petha. He wants to arrange them in stacks such that each stack has the same number of Pethas, and the arrangement takes the least area of the tray. We need to find the number of Pethas that can be placed in each stack for thisRead more
Understanding the Problem
The shopkeeper has 660 Kesar Petha and 510 Paan Petha. He wants to arrange them in stacks such that each stack has the same number of Pethas, and the arrangement takes the least area of the tray. We need to find the number of Pethas that can be placed in each stack for this purpose.
This problem essentially asks for the greatest common divisor (GCD) of the two numbers, which will give us the largest stack size that can be used to arrange both types of Petha in an optimal manner.
Solving the Problem
Let’s find the GCD of 660 and 510.
We can use the Euclidean algorithm to find the GCD:
1. Divide 660 by 510 and find the remainder: \(660 = 510 \times 1 + 150\)
2. Now, divide 510 by the remainder from the previous step: \(510 = 150 \times 3 + 60\)
3. Continue this process until the remainder is 0: \(150 = 60 \times 2 + 30\) and \(60 = 30 \times 2 + 0\)
The last non-zero remainder is 30, so the GCD of 660 and 510 is 30.
Conclusion
The number of Pethas that can be placed in each stack for this purpose is 30.
See lessThe cost price of a table and a chair together is Rs. 690. If the table costs 30% more than the chair, then find the cost price of the table and the chair respectively.
Understanding the Problem We are given: - The combined cost price of a table and a chair is Rs. 690. - The table costs 30% more than the chair. We need to find the individual cost prices of the table and the chair. Solving the Problem Let's denote the cost price of the chair as \(C\) rupees. Since tRead more
Understanding the Problem
We are given:
– The combined cost price of a table and a chair is Rs. 690.
– The table costs 30% more than the chair.
We need to find the individual cost prices of the table and the chair.
Solving the Problem
Let’s denote the cost price of the chair as \(C\) rupees.
Since the table costs 30% more than the chair, the cost price of the table is \(C + 0.30C = 1.30C\) rupees.
The combined cost price of the table and chair is given as Rs. 690, so we can write the equation:
\[ C + 1.30C = 690 \]
Simplifying:
\[ 2.30C = 690 \]
Dividing both sides by 2.30:
\[ C = \frac{690}{2.30} \]
\[ C = 300 \]
Now that we know the cost price of the chair is Rs. 300, we can find the cost price of the table:
\[ \text{Cost price of the table} = 1.30C = 1.30 \times 300 = 390 \]
Conclusion
The cost price of the table is Rs. 390, and the cost price of the chair is Rs. 300.
See lessA and B are partners in a business. They invest in the ratio of 4 : 9, at the end of 6 months A withdraws. If they receive profits in the ratio of 4 : 9, then find how long B’s investment was used.
Understanding the Problem In a partnership business, A and B invest in the ratio of 4:9. A withdraws his investment after 6 months. Despite A's withdrawal, they still receive profits in the same ratio as their initial investments (4:9). We need to find out for how long B's investment was used. SolviRead more
Understanding the Problem
In a partnership business, A and B invest in the ratio of 4:9. A withdraws his investment after 6 months. Despite A’s withdrawal, they still receive profits in the same ratio as their initial investments (4:9). We need to find out for how long B’s investment was used.
Solving the Problem
Let’s denote the period for which B’s investment was used as \(x\) months.
The profit earned by a partner in a business is directly proportional to the product of their investment and the time period for which the investment is made.
Given that A’s investment was used for 6 months and B’s investment was used for \(x\) months, we can write the following equation based on the proportion of their profits:
\[ \frac{\text{A’s investment} \times \text{A’s time}}{\text{B’s investment} \times \text{B’s time}} = \frac{4}{9} \]
Plugging in the values:
\[ \frac{4 \times 6}{9 \times x} = \frac{4}{9} \]
Simplifying:
\[ \frac{24}{9x} = \frac{4}{9} \]
\[ 24 = 4x \]
\[ x = \frac{24}{4} = 6 \]
Conclusion
B’s investment was used for 6 months.
See lessIn a particular school, out of total 640 boys that include all the age-groups, 60% of the boys below 18 were enrolled. Out of them, 50% attended the school irregularly. If 120 boys among them were regular, how many boys were there in the school who are above 18?
Understanding the Problem We are given the following information about a school: - There are a total of 640 boys in the school. - 60% of the boys below 18 years old were enrolled. - Out of the enrolled boys below 18, 50% attended the school irregularly. - Among the enrolled boys below 18, 120 were rRead more
Understanding the Problem
We are given the following information about a school:
– There are a total of 640 boys in the school.
– 60% of the boys below 18 years old were enrolled.
– Out of the enrolled boys below 18, 50% attended the school irregularly.
– Among the enrolled boys below 18, 120 were regular attendees.
We need to find out how many boys in the school are above 18 years old.
Solving the Problem
Let’s denote the number of boys below 18 years old as \( B_{\text{below 18}} \).
According to the problem, 60% of these boys were enrolled, so the number of enrolled boys below 18 is:
\[ E_{\text{below 18}} = 0.60 \times B_{\text{below 18}} \]
Out of these enrolled boys, 50% attended the school irregularly, so the number of regular attendees is:
\[ R_{\text{below 18}} = 0.50 \times E_{\text{below 18}} \]
But we know that there were 120 regular attendees, so:
\[ R_{\text{below 18}} = 120 = 0.50 \times E_{\text{below 18}} \]
Solving for \( E_{\text{below 18}} \):
\[ E_{\text{below 18}} = \frac{120}{0.50} = 240 \]
Now, we can find \( B_{\text{below 18}} \) using the equation:
\[ B_{\text{below 18}} = \frac{E_{\text{below 18}}}{0.60} = \frac{240}{0.60} = 400 \]
Since there are a total of 640 boys in the school, the number of boys above 18 years old is:
\[ B_{\text{above 18}} = \text{Total boys} – B_{\text{below 18}} = 640 – 400 = 240 \]
Conclusion
There are 240 boys in the school who are above 18 years old.
See less