
-10 sin(x) = -4 csc(x) + 3
Recall that csc(x) = 1/sin(x) :
-10 sin(x) = -4/sin(x) + 3
Multiply both sides by sin(x) :
-10 sin²(x) = -4 + 3 sin(x)
Move everything to one side:
10 sin²(x) + 3 sin(x) - 4 = 0
Factorize the left side:
(2 sin(x) - 1) (5 sin(x) + 4) = 0
Then we have two cases,
2 sin(x) - 1 = 0 or 5 sin(x) + 4 = 0
Solve for sin(x) :
sin(x) = 1/2 or sin(x) = -4/5
Solve for x :
• if sin(x) = 1/2, then
x = arcsin(1/2) + 2nπ or x = π - arcsin(1/2) + 2nπ
x = π/6 + 2nπ or x = 5π/6 + 2nπ
• if sin(x) = -4/5, then
x = arcsin(-4/5) + 2nπ or x = π - arcsin(-4/5) + 2nπ
x = -arcsin(4/5) + 2nπ or x = π + arcsin(4/5) + 2nπ
(where n is any integer)