Question

Find maxima and minima of :
(i) y= x^2 + 3x + 2
(ii)y= sinx

Answer 1

Explanation:

for maximum or minimum dy/dx =0

1) f(x) = x^2 +3x +2

dy/dx =2x + 3

2x+3=0

x= -3/2 = -1.5

second derivative of f(x) is 2 which is >0

so it has minima value

y= -0.25

2) f(x)= sinx

we know that -1 <= sinx <= 1

so maxima is 1

minima is -1