I need some help with this trig problem?

Okay, first draw a right angled triangle, and label the opposite, adjacent and hypotenuse sides. cos x = adj/hyp = 7/25. Although the adj and hyp can be any multiples of 7 and 25, assume them to be 7 and 25. Now, opp = 24, because (7,24,25) is a Pythagorean triple. Hence, tan x = opp/adj = 24/7.

tan 2x = (2 tan x) / (1 - tan^2 x) = (2 * 24/7) / (1 - (24/7)^2)

= (48/7) / (-527/49)

= (48 * 49) / (7 * -527)

= 2352/-3689

= -336/527.

It's given that tan x is negative, and -336/527 is also negative.

I hope that helps. :)

me07.

I am going to assume you mean tan(2x)???? I mean, where does theta come from?

cosine is positive and tan is negative. this means that the angle is in the fourth quadrant and between 3pi/2 and 2pi (270 degrees and 360).

cos(x) = 7/25

x = -1.287 radians (-73.74 degrees)

tan(2x) = tan(-147.48) = 0.63757

You can also write angle as x = 286.26 degrees

tan(2x) = tan(572.52) = tan(212.52) = 0.63757