4secx10 x is in quadrant II find sin2x cos2x and tan2xSoluti

4.sec(x)=-10, x is in quadrant II

-find sin(2x), cos(2x) and tan(2x)

Solution

4.sec(x) = -10,    x is in quadrant II

sec(x) = -2.5

cos(x) = -0.4

sin(x) = sqrt(1 – 0.4^2) = 0.917

tan(x) = - 2.2925

Now

sin(2x) = 2*sinx* cosx = -0.7336

cos(2x) = 2cos²(x) – 1 = -0.68

tan(2x) = 2 tan(x) / (1 - tan^{^2}(x)) = 1.077