sinx = 2cosx
tanx = 2
tanx > 0 in QI or QIII, so there are two values for x.
Verify this at
http://www.wolframalpha.com/input/?i=solve+sinx+%3D+2cosx
The number of values in the interval –π ≤ x ≤ π that satisfy the equation sin x = 2 cos x is
1
2
3
4
0
1 answer