Worked example
Differentiate f(x) = 3x4.
Answer & why
Answer: 12x3
The power rule gives 3 × 4 × x3 = 12x3.
Grade 12 · Math
Use the power rule on a constant times a positive integer power.
8 generated examples + worked example

Answer: 12x3
The power rule gives 3 × 4 × x3 = 12x3.
8 reproducible examples from this math generator. Choose New examples for another set.
Question 1
Multiply by the exponent, then reduce the exponent by one.
Answer: 32x3
The power rule gives d/dx(8x4) = 8 × 4 × x4 − 1 = 32x3.
Question 2
Multiply by the exponent, then reduce the exponent by one.
Answer: 40x4
The power rule gives d/dx(8x5) = 8 × 5 × x5 − 1 = 40x4.
Question 3
Multiply by the exponent, then reduce the exponent by one.
Answer: 14x1
The power rule gives d/dx(7x2) = 7 × 2 × x2 − 1 = 14x1.
Question 4
Multiply by the exponent, then reduce the exponent by one.
Answer: 10x1
The power rule gives d/dx(5x2) = 5 × 2 × x2 − 1 = 10x1.
Question 5
Multiply by the exponent, then reduce the exponent by one.
Answer: 30x4
The power rule gives d/dx(6x5) = 6 × 5 × x5 − 1 = 30x4.
Question 6
Multiply by the exponent, then reduce the exponent by one.
Answer: 27x2
The power rule gives d/dx(9x3) = 9 × 3 × x3 − 1 = 27x2.
Question 7
Multiply by the exponent, then reduce the exponent by one.
Answer: 35x4
The power rule gives d/dx(7x5) = 7 × 5 × x5 − 1 = 35x4.
Question 8
Multiply by the exponent, then reduce the exponent by one.
Answer: 12x3
The power rule gives d/dx(3x4) = 3 × 4 × x4 − 1 = 12x3.