Solve 2sinxcosx-sqrt2cosx=0 for 0 <=x<=360degree?

1 Answer
Nghi N
May 17, 2018

pi/4; pi/2; (3pi)/4; (3pi)/2

Explanation:

2sin x.cos x - sqrt2cos x= 0
cos x(2sin x - sqrt2) = 0
Either factor should be zero:
a. cos x = 0
Unit circle give 2 solutions for x:
x = pi/2, and x = (3pi)/2
b. 2sin x - sqrt2 = 0
sin x = sqrt2/2
Trig table and unit circle give 2 solutions for x
x = pi/4, and x = (3pi)/4

Related questions
Impact of this question
1314 views around the world
You can reuse this answer
Creative Commons License