The point on the curve $y=x^2+7$ nearest to point (3, 7) is:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → (1, 8)
$y = x^2 + 7$
$D^2 = (x-3)^2 + (x^2+7-7)^2 = (x-3)^2 + x^4$
$\frac{d}{dx}(D^2) = 2(x-3) + 4x^3$
$= 2x - 6 + 4x^3 = 0$
$2x^3 + x - 3 = 0$
$x=1 \Rightarrow 2(1)^3+1-3=0$
$y = 1^2 + 7 = 8$
$\text{Nearest point} = (1,8)$