Question

Calcule o limite:

a) lim r²+2r-3 / r²+7r+12
x→-3
b) lim √x - 5 /x-25
x→25

Answer 1

Olá Daiany

a) 

lim (r² + 2r - 3) / (r² + 7r + 12) 
r -->-3

derivada

lim (2r + 2)/(2r + 7) = -4/1 = -4 
r -->-3 

b) 

lim(√x - 5)/(x - 25) = (√x - 5)/((√x + 5)(√x - 5)) =
x-->25

1/(√x + 5) = 1/(√25 + 5) = 1/10