SOLUTION: Find the value of x in degree 5 (sin ^2)x + 12 sin x + 4 = 0

Question 858018: Find the value of x in degree 5 (sin ^2)x + 12 sin x + 4 = 0
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Find the value of x in degree 5 (sin ^2)x + 12 sin x + 4 = 0
----------
5sin^2(x) + 12sin(x) + 4 = 0
--------
Factor:
5sin^2(x) + 10sin(x)+2sin(x) + 4 = 0
-----
5sin(x)[sin(x)+2][2((sin(x)+2)] = 0
-----
(sin(x)+2)(5sin(x)+2] = 0
-------------------------------
sin(x) = -2 (extraneous)
sin(x) = -2/5 = -0.4
=========================
Ans: x = arcsin(-0.4) = -23.58 degrees or 180+23.58 degrees
===============================================
Cheers,
Stan H.
RELATED QUESTIONS
Find the exact value if 0 < x < pi/2 and 0 < y < pi/2 ; sin(x+y) if sin(x) = 3/5 and... (answered by fractalier)

(Trigonometric identities) Find the value of each expression using the given... (answered by ewatrrr)

if sin x= 4/5, where 0 (answered by edjones)
If sin x<0 and tan x=-4/5, find the exact value of sec x (answered by lwsshak3)
if sec(x) = -5/4 and sin(x) < 0, find the exact value of... (answered by harpazo,lwsshak3)
Find the exact value of sin (x+y) if sin x = 4/5 in Quadrant II and tan y = 12/5 in... (answered by lwsshak3)
please help me solve this equation: solve exactly: sin(x) + 4csc(x) + 5=0 I have... (answered by stanbon)
If sin x= -4/5 and x is in quadrant III, find the value of... (answered by jrfrunner)
Find all solutions of the equation in the interval [0, 2π) sin(x + π/4)... (answered by lwsshak3)