Question

The curve with equation y = x + 6x² +5 has two turning points. (b) Work out the coordinates of these two turning points. Show your working clearly.​

Answer 1

Hello,

Explanation:

`y=x^3+6x^2+5\\y'=3x^2+12x\\y'=0 : 3x(x+4)=0 \ \Longrightarrow\ x=0\ or\ x=-4\\if\ x=0 \ \Longrightarrow\ y=0^3+6*0^2+5=5\\if\ x=-4 \ \Longrightarrow\ y=(-4)^3+6*(-4)^2+5=-64+96+5=37\\The\ two\ turning\ points\ are \ (0,5)\ and\ (-4,37)`

Answer 2

(0,5) and (-4,37)

Explanation:

3ₓ² + 12ₓ =0

x=0 and x=4