AP EAMCET202315 May 2023Morning ShiftMathematicsApplication of DerivativesActual
If A = x / 9 x x ^2+20 and f : A R is defined by f(x)=2 x^3-15 x^2+36 x-48 , then the maximum value of f(x) is
Options
- A-20
- B7
- C20
- D-16
Correct answer
B. 7
Step-by-step solution
aligned & Given A = x: 9 x x ^2+20 & A = x: x [4,5] =[4,5] & Given f(x)=2 x^3-15 x^2+36 x-48 & f^ (x)=6 (x^2-5 x+6 )=6(x-3)(x-2) aligned For maxima or minima f^ (x)=0 aligned & x=3,2 & but A=[4,5] aligned Hence f(x) is increasing function in A =[4,5] Therefore maximum value of f(x) will be obtained at x=5 f(5)=7