Question

Which expression is equivalent to sec2xcot2x?

A.
sin2x

B.
csc2x

C.
`(1)/(cos^2x)`

D.
`(1)/(tan^2x)`

Answer 1

Answer:

Option B is correct answer.

Step-by-step explanation:

We need to solve the expression sec2xcot2x.

We know sec x = 1/ cos x and cot x = 1/ tan x and tan x = sin x/cos x and 1/tanx = cosx /sinx

Since in question we 2x instead of x so, replacing x with 2x and Putting values:

$sec2x\,\, cot2x\\=\frac{1}{cos 2x} * \frac{1}{tan 2x} \\=\frac{1}{cos 2x} * \frac{cos2x}{sin2x}\\=\frac{1}{sin 2x}\\=csc2x$

So, Option B is correct answer.

Answer 2

Answer:

b

Step-by-step explanation: