Question

Factor the trigonometric expression:

cos^2(x)sec(x)-4cos(x)sec(x)-21sec(x)

Answer 1

Wouldn't sec(x) be a common factor?

Answer 2

that's what i thought... but for the input it has an empty box* empty box
*empty box

Answer 3

and I'm not sure what the 3 would be..

Answer 4

If you factor out a sec(x), you get:

sec(x) [cos^2 (x) - 4 cos(x) - 21}


But that second expression may be factorable again.

Answer 5

oh ok! thank you! could you factor the second one into 4cos(x) [ cos(x)]? but then where would the 21 go

Answer 6

cosx=7 cosx =-3 right?
and 0

Answer 7

sub u for cos
then solve like a regular equation?

Answer 8

secx (cos x - 7)(cos x +3)

Answer 9

Perfect!

Answer 10

oh my gosh, thank you!!!!

Answer 11

welcome.

Answer 12

Thank you to both of you @Easyaspi314 and @sarsteele !!!