Turning points of the curve y = (9x^2 +1)/3x+2
Use quotient rule to differentiate:
dy/dx = (18x(3x+2) - 3(9x2+1))/(3x+2)2
set dy/dx=0:
54x2 + 36x - 27x2 - 3 = 0
9x2 + 12x - 1 = 0
solve quadratic to obtain values of x, and then find corresponding values of y by subbing these x values into original equation.
To find if max or min, differentiate formula twice, then sub in values of x. If f''x > 0, then minimum. If f''x < 0, maximum.
JH
