How would i go about working out: 1. cos(x) + sin(x) = (1/3), -pi < x < pi 2. ln(y+1) - ln(y) = 0.85
Follow Math Help Forum on Facebook and Google+
Hello, For the first one, I'd make a substitution with u=cos(x). As cos²(x)+sin²(x)=1, sin(x)=sqrt(1-cos²(x))=sqrt(1-u²) Thus we have Square the whole equation and solve for u, then deduct the values for x. For the second one : So it's equivalent to :
Hello, Stylis10! Another approach to #1 . . . Divide by And we have: . . . . . . . . . . . . . . . . . . Hence: . . . Therefore: .
View Tag Cloud