Question

Prove the identity showing each step as rule.
secx-sinxtanx=cosx

Answer 1

try changing everyhthing to sin and cos
1 / cos x -( sin x * sinx) / cos x
=(1 - sin^2 x) / cos x

and what is (1 - sin^x) equal to ?

Answer 2

I don't understand the step "=(1 - sin^2 x) / cos x" What rule is used to get here?

Answer 3

I see it now, they share a common denominator of cosx so they are combined, thank you.

Answer 4

yw