Solve for x (where 0<x<360) 2sin^2(x) - sin(x) - 1 = 0

Factorise the equation (the equation is quadratic in sin(x) )2 sin2(x) - sin(x) - 1 = 0(2sin(x) + 1)(sin(x) - 1) = 0Work out the solutions to the quadratic equation2sin(x) +1 = 0 or sin(x) - 1 = 0sin(x) = -1/2 or sin(x) = 1Determine the possible values of x, remembering to include any values generated due to the cyclic nature of the sin() functionsin(x) = 1 ---> x = 90sin(x) = -1/2 ---> x = -30 This value is outside of our given range, but by considering the sin curve, we can determine that x = 330 or x = 210Therefore the solutions to our equation are x=90 x=210 x=330

Related Maths A Level answers

All answers ▸

How would I differentiate y=2(e^x)sin(5x) ?


Given that dy/dx=6-8x+x^4 and that x=1 when y=4. Find an expression for y in terms of x.


If y = sec(z)tan(z)/sqrt(sec(z)) then find the indefinite integral of y with respect to z.


Use the identity for sin(A+B) to find the exact value of sin 75.