Question

Evaluate 8/cot2 theta - 8/cos2 theta

Answer 1

If it is for square and cos square then ans in attachment

Hope this help you

Answer 2

The value of $\dfrac{8}{\cot^2 \theta}-\dfrac{8}{\cos^2 \theta}$ is equal to - 8.

Step-by-step explanation:

We have,

$\dfrac{8}{\cot^2 \theta}-\dfrac{8}{\cos^2 \theta}$

To find, the value of $\dfrac{8}{\cot^2 \theta}-\dfrac{8}{\cos^2 \theta}$ = ?

∴ $\dfrac{8}{\cot^2 \theta}-\dfrac{8}{\cos^2 \theta}$

$=\dfrac{8}{\dfrac{\cos^2 \theta}{\sin^2 \theta} }-\dfrac{8}{\cos^2 \theta}$

Using the trigonometric identity,

$\cot A}=\dfrac{\cos A}{\sin A}$

$=\dfrac{8\sin^2 \theta}{\cos^2 \theta}-\dfrac{8}{\cos^2 \theta}$

$= \dfrac{8}{\cos ^2 \theta} (\sin^2 \theta-1)$

$= \dfrac{8}{\cos ^2 \theta} (-\cos ^2 \theta)$

Using the trigonometric identity,

$\sin^2 A+\cos^2 A=1$

= - 8

Thus, the value of $\dfrac{8}{\cot^2 \theta}-\dfrac{8}{\cos^2 \theta} = - 8$