SOLUTION: PLEASE HELP ME ! Find sin 2x, cos 2x, and tan 2x from the given information. tan x = − 15/8 , x in Quadrant II

Algebra.Com
Question 1026523: PLEASE HELP ME !
Find sin 2x, cos 2x, and tan 2x from the given information.
tan x = − 15/8 , x in Quadrant II

Answer by rothauserc(4718)   (Show Source): You can put this solution on YOUR website!
tan^(-1) of -15/8 is approx -62 degrees
:
trig functions are periodic - we are looking for the angle in the second quadrant which is equivalent to -62 degrees, that angle is 180-62 = 118 degrees
:
sin(118) = 0.88
cos(118) = -0.47
:
sin 2x = 2sin(x)cos(x)
sin 2x = 2(0.88)(-0.47) = -0.83
:
cos 2x = 2cos^2(x) - 1
cos 2x = 2(-0.47)^2 - 1 = -0.56
:
tan 2x = (2tan(x)) / (1 - tan^2(x))
tan 2x = (2(-15/8)) / (1 - (-15/8)^2) = 1.49
:

RELATED QUESTIONS

Find sin 2x, cos 2x, and tan 2x from the given information. tan x = − 15/8 x... (answered by lwsshak3)
Please help me with this equation. Find sin(2x), cos(2x), and tan(2x) from the given... (answered by math_tutor2020,Theo,MathTherapy)
Find sin 2x, cos 2x, and tan 2x from the given information. tan x = − 12/5 , x... (answered by ewatrrr)
Find sin 2x, cos 2x, and tan 2x from the given information. tan x = − 12/5, x in (answered by lwsshak3)
Find sin 2x, cos 2x, and tan 2x from the given information. sec x = 8, x in Quadrant... (answered by tommyt3rd)
Find sin (2x), cos (2x), and tan (2x) from the given information. tan (x) = 1/2 x... (answered by lwsshak3)
Find sin 2x, cos 2x, and tan 2x from the given information. sec x = 4, x in Quadrant... (answered by Theo)
Find sin 2x, cos 2x, and tan 2x from the given information. csc x = 6, tan x < 0 sin... (answered by lwsshak3)
Find sin (2x), cos (2x), and tan (2x) from the given information. sec (x) = 10 x... (answered by lwsshak3)