WAEC - Mathematics (2012 - No. 17)
If cos(x + 40)o = 0.0872, what is the value of x?
85o
75o
65o
45o
คำอธิบาย
cos(x + 40)o = 0.0872
x + 40 = cos-10.0872
x + 40o = 84.99o
x = 84.99o - 40o
x = 44.99
x = 45o
x + 40 = cos-10.0872
x + 40o = 84.99o
x = 84.99o - 40o
x = 44.99
x = 45o