GCSE Secondary Maths Age 13-17 - Algebra: Functions - Explained

The video tutorial introduces functions f and g, with f(x) = 2/x^2 and g(x) = 4x^3, and explains how to solve problems involving these functions. Part A covers calculating f(-5) by substituting -5 into the function and ensuring correct squaring. Part B discusses composite functions, specifically fg(1), emphasizing the importance of order in solving such problems. The tutorial highlights the need for understanding these new GCSE topics, as they are not found in previous exam papers.

What is the function f(x) as described in the video?

• f(x) = 2x^2

• f(x) = x^2/2

• f(x) = 2/x^2

• f(x) = 4x^3

How do you calculate f(-5) for the function f(x) = 2/x^2?

• Subtract 5 from 2 and then square the result

• Add 5 to 2 and then square the result

• Multiply -5 by 2 and then square it

• Substitute -5 into x and calculate 2/(-5)^2

What is the result of f(-5) for the function f(x) = 2/x^2?

• 2/25

• 2/10

• 2/50

• 2/5

In a composite function fg(x), which function should be evaluated first?

• g(x)

• f(x)

• It doesn't matter

• Both simultaneously

What is the final result of fg(1) when f(x) = 2/x^2 and g(x) = 4x^3?

• 1/32

• 1/16

• 1/4

• 1/8