Question

simplify tan x cos x

Answer 1

Remember tangent is just sin(x)/cos(x)

Answer 2

so its cos x (sin x / cos x) ?

Answer 3

Correct, now what happens when you go ahead and multiply the cosine?

Answer 4

sin x

Answer 5

That's it. The cosines cancel.

Answer 6

okay cool
what bout sec y sin (pi/2-y)? IDK how to do this at all

Answer 7

\[\sec(y)\sin(\frac{\pi}{2-y})\]
??

Answer 8

but isnt it like pi/2 - y not pi/ 2-y

Answer 9

sin(pi/2-y)=cos y
sec y= 1/cos y

Answer 10

Ok, so rewrite secant as 1/cos

Answer 11

Then you can use a fancy pants trig identity.

Answer 12

cos y 1/cos y

Answer 13

Right?