Answer:
(fog)(x) = 2x² - 10x + 15
Explanation:
- (fog)(x) is called a composite function, where x in f(x) substituted by g(x).
- The range of g(x) is the domain of f(x)
Let us solve our question
∵ f(x) = 2x + 3
∵ g(x) = x² - 5x + 6
→ We need to compute (fog)(x)
∴ Substitute x in f(x) by g(x)
∵ (fog)(x) = 2(x² - 5x + 6) + 3
→ Multiply the bracket by 2
∵ 2(x² - 5x + 6) = 2(x²) - 2(5x) + 2(6)
∴ 2(x² - 5x + 6) = 2x² - 10x + 12
→ Substitute it in the composite function above
∴ (fog)(x) = 2x² - 10x + 12 + 3
→ Add the like terms 12 and 3
∴ (fog)(x) = 2x² - 10x + 15