Substitute n cosx in for those two answers. Subtract 1 from both sides of the equation. N 2-2n 1 Now the clever bit.
Since all these terms are equal to each other it actually means.
Solve 1 x 2 10x 16 0 2 y 2 4y 21 0 3 p 2 6p 7 0 4 n 2 2n 1 0 5 t 2 t 42 6 k 2 10k 25 0. N 2. Take the coefficient of n which is 2 divide by two giving 1 and finally square it giving 1 Add 1 to both sides of the equation. N 2-2n1 0 Adding 1 has completed the left hand side into a perfect square.