Multiplying trig functions

If(secx)(tanx) < 0, which of the following must be true?

I. tanx <0

II. scsx cotx < 0

III. x is in the third or fourth quadrant

So I first simplified secx * tanx into sinx/cos^2x using the property that tanx = sinx/cosx, and then i graphed it on my calculator, but I'm not sure what to do next.

Re: Multiplying trig functions

Quote:

Originally Posted by

**rasen58** If(secx)(tanx) < 0, which of the following must be true?

I. tanx <0

II. scsx cotx < 0

III. x is in the third or fourth quadrant

So I first simplified secx * tanx into sinx/cos^2x using the property that tanx = sinx/cosx, and then i graphed it on my calculator, but I'm not sure what to do next.

If then one of the factors is negative and one is positive.

Think in terms of quadrants.

Re: Multiplying trig functions