1. Tardigrade
  2. Question
  3. Mathematics
  4. If f: R → R and g: R → R defined by f(x) = 2x + 3 and g(x ) = x2 + 7, then the value of x for which f(g(x)) = 25

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. If $f : R \to R$ and $g : R \to R$ defined by f(x) = 2x + 3 and $g(x ) = x^2 + 7$, then the value of x for which f(g(x)) = 25

Relations and Functions - Part 2

Solution:

$f (g(x)) = f (x^2 + 7) = 2(x^2 + 7) + 3 = 25$
$\Rightarrow \, 2x^2 = 8 \, \Rightarrow \, x = \pm 2$