Question

06-Sendo f(x) = x2 + 4, f: RR, calcule x para que se tenha:
a) f(x) = 0
b) f(x) = 5
c) f(x) = 12
d) f(x) = 12​

Answer 1

a)

${x}^{2} + 4 = 0 \\ {x}^{2} = - 4 \\x∉ℝ$

b)

${x}^{2} + 4 = 5 \\ {x}^{2} = 5 - 4 \\ {x}^{2} = 1 \\ x = 1.$

c)

${x}^{2} + 4 = 12 \\ {x}^{2} = 12 - 4 \\ {x}^{2} = 8 \\ x = \sqrt[2]{8} = 2 \sqrt{2} .$

-BURNS