If frac{cos A}{3} = frac{cos B}{4} = frac{1}{ | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(C) Given $\frac{\cos A}{3} = \frac{1}{5} \implies \cos A = \frac{3}{5}$.Since $-\frac{\pi}{2} < A < 0$, $A$ lies in the fourth quadrant, so $\sin A$

Vedclass · Accepted Answer

$-4$

Vedclass · Answer

(C) Given $\frac{\cos A}{3} = \frac{1}{5} \implies \cos A = \frac{3}{5}$.Since $-\frac{\pi}{2} $\sin A = -\sqrt{1 - \cos^2 A} = -\sqrt{1 - (\frac{3}{5})^2} = -\sqrt{1 - \frac{9}{25}} = -\sqrt{\frac{16}{25}} = -\frac{4}{5}$.Given $\frac{\cos B}{4} = \frac{1}{5} \implies \cos B = \frac{4}{5}$.Since $-\frac{\pi}{2} $\sin B = -\sqrt{1 - \cos^2 B} = -\sqrt{1 - (\frac{4}{5})^2} = -\sqrt{1 - \frac{16}{25}} = -\sqrt{\frac{9}{25}} = -\frac{3}{5}$.Now, calculate $2 \sin A + 4 \sin B = 2(-\frac{4}{5}) + 4(-\frac{3}{5}) = -\frac{8}{5} - \frac{12}{5} = -\frac{20}{5} = -4$.

If $\frac{\cos A}{3} = \frac{\cos B}{4} = \frac{1}{5}$, $-\frac{\pi}{2} < A < 0$, and $-\frac{\pi}{2} < B < 0$, then the value of $2 \sin A + 4 \sin B$ is

Similar Questions

$\tan A = \frac{-60}{11}$ and $A$ does not lie in the $4^{\text{th}}$ quadrant. $\sec B = \frac{41}{9}$ and $B$ does not lie in the $1^{\text{st}}$ quadrant. If $\operatorname{cosec} A + \cot B = K$,then $24K =$

$\tan 1^{\circ} \times \tan 2^{\circ} \times \tan 3^{\circ} \times \cdots \times \tan 89^{\circ} = $

$\frac{1+\tanh \frac{x}{2}}{1-\tanh \frac{x}{2}}$ is equal to

$\left(\frac{\sin 35^{\circ}}{\cos 55^{\circ}}\right)^2+\left(\frac{\cos 55^{\circ}}{\sin 35^{\circ}}\right)^2-2 \cos 30^{\circ}=$

If $A, B, C, D$ are the angles of a cyclic quadrilateral taken in order,then $\cos(180^{\circ} + A) + \cos(180^{\circ} - B) + \cos(180^{\circ} - C) - \sin(90^{\circ} - D) =$

Vedclass Test Series

Exam Paper Generator

Online Exam Module