Question

write the trig expression in terms of Sine and cosine, then simplify : tan^2(x)-Sec^2(x)

Answer 1

hold on:

Answer 2

where do I go from there?

Answer 3

tan = sinx/cosx, so:
tan^2 = (sinx/cosx)(sinx/cosx) = sin^2x/cos^2x

Answer 4

hold on:

Answer 5

what happened to sin^2(x) in the last part???

Answer 6

What do you mean?

Answer 7

you went from Sin^2(x) -1=Cos^2(x) to Cos^2(x)/Cos^2(x)=-1... idk how you got there

Answer 8

sin^2(x) + cos^2(x) = 1

sin^2(x) + cos^2(x) - 1 = 0
-cos^2(x) -cos^2(x)

sin^2(x) -1 = -cos^2(x)

Answer 9

Do you know this trig identity?

Answer 10

Are you still following?

In this case, cos^2(x) is a common denominator, so you subtract the fraction like any other fraction. You subtract the numerator and keep the demominator of cos^2(x)