Question

help please the image is below

Answer 1

any help is appreciated :)

Answer 2

You should use the relations:

\[\sec\theta=\frac{1}{\cos\theta}\]
\[1+\tan^2\theta=\frac{1}{\cos^2\theta}\]

Answer 3

@John_ES what does cos2theta turn into

Answer 4

1-sin^2theta?

Answer 5

tan theta = sin theta/cos theta

tan sq theta = sin sq theta/cos sq theta

\[\frac{ \sec \theta }{ 1 + \tan^2 \theta }\]

Answer 6

You don't need to transform cos2theta, as the problem ask you to put the expression in function of cos.

Answer 7

wait so what do i need to do next i'm confused

Answer 8

When their a lot of tan's and sec's and cot's in the equation convert them to cos and sin.

Answer 9

Yes, you have to convert all the expressions. But in this case, it is simpler, as you only need to put the sec as a cos, and the tan2 as a cos2. The simplify to get the final result.

Answer 10

how is tan2 turned into cos2?

Answer 11

is it bc tan2theta = to sec2theta then it's 1/costheta

Answer 12

i meant sectheta *

Answer 13

This way,\[1+\tan^2\theta=\frac{1}{\cos^2\theta}\]