Question

Prove The Identity:

1-tan^4 θ = 2 sec^2 θ - sec ^4 θ

Answer 1

factor both sides:

Answer 2

\[
1- \tan^4 x =(1-\tan^2 x)(1+\tan^2 x)=(1-\tan^2 x) \sec^2 x=\\
\left( 1- \frac {\sin^2 x}{\cos^ x} \right)\sec^2 x
\]
The rest should be easy

Answer 3

Given: 3x - 2 ≤ 2x + 1.



Choose the solution set.

{x | xR, x ≤ -3}
{x | xR, x ≤ -1}
{x | xR, x ≤ 1}
{x | xR, x ≤ 3}

Answer 4

i have no clue about this question, i'm only in 9th grade math. So, are the solutions the answers?

Answer 5

\[1- \tan^4 x =(1-\tan^2 x)(1+\tan^2 x)=(1-\tan^2 x) \sec^2 x=\\
\left( 1- \frac {\sin^2 x}{\cos^2 x} \right)\sec^2 x=\\
\left( \frac{\cos^2 x- \sin^2 x}{\cos^2 x}\right)\sec^2 x=\\
\left(\frac{2\cos^2 x -1}{\cos^2 x}\right)\sec^2 x=\\
\left(2 -\sec^2 x\right)\sec^2 x=\\
2 \sec^2 x - \sec^4 x
\]

Answer 6

thanks!

Answer 7

@Camoguy937 did you understand my solution?

Answer 8

yes, thanks!

Answer 9

yw