How do you solve sin(x/2)=sqrt2/2sin(x2)=22?

1 Answer
Dec 30, 2016

pi/2 + 4kpiπ2+4kπ
(3pi)/4 + 4kpi3π4+4kπ

Explanation:

sin (x/2) = sqrt2/2sin(x2)=22
Trig table gives:
sin x/2 = sqrt2/2sinx2=22 --> arc x/2 = pi/4x2=π4.
Unit circle gives another arc x that has the same sin value:
x/2 = pi - pi/4 = (3pi)/4x2=ππ4=3π4

a. x/2 = pi/4 + 2kpix2=π4+2kπ -->
x = (2pi)/4 + 4kpi = pi/2 + 4kpix=2π4+4kπ=π2+4kπ

b. x/2 = (3pi)/4 + 2kpix2=3π4+2kπ
x = (6pi)/4 + 4kpi = (3pi)/2 + 4kpix=6π4+4kπ=3π2+4kπ