Question

find the derivative of x²-2 at x=10?
incorrect answers will be reported..

Answer 1

Let y=x^2-2, Hence dy/dx=d/dx(x^2-2)=2x ;at x=10 will be 2×10=20.

Answer 2

Step-by-step explanation:

$f(x) = x ^{2} - 2 \\ f(x + h) = (x + h)^{2} - 2 \\ Now, \\ \\ f'(x)= \frac{f(x + h) - f(x)}{h} \\ \displaystyle \lim_{h \to 0} = \frac{(x + h)^{2} - 2 - (x^{2} - 2)}{h} \\ \displaystyle \lim_{h \to 0} = \frac{x ^{2} + h^{2} + 2xh-2 - x^{2} + 2}{h} \\\displaystyle \lim_{h \to 0} = \frac{\cancel{x ^{2}} + h ^{2} + 2xh \: \cancel{ -2} \: \: \: \cancel{-x^{2}} \: \cancel { + 2}}{h} \\ \displaystyle \lim_{h \to 0} = \frac{h^{2} + 2xh }{h} \\\displaystyle \lim_{h \to 0} = h + 2x \\ = 0 + 2x \\ = 2x$

f'(x) = 2x

f'(10) = 2*10

‎‎‎‎‎‎ ‎ ‎ ‎‎ ‎ ‎ ‎‎ ‎ ‎=20

Kindly thanks and rate 5 star✌️