The method used to find the derivative (dy/dx) of the equation is to:
"Multiply the coefficient of x by the power then deduct the power x is raised to by 1"
Step 1: 3x^4
Carry the power of 4 down and multiply it by the 3 (coefficient of x in this case), then deduct the power by 1 i.e. 3x^4 becomes 12x^3
Step 2: 10x^2
Repeat this for 10x^2 which becomes 20x^1 which is the same as 20x
Step 3: 7x
Think of 7x as 7x^1, so multiply the 7 by the power of 1 and deduct the power by 1 hence you get 7x^0.
Anything to the power of 0 equals 1 so essentially you end up with 7 x 1 = 7Therefore dy/dx = 12x^3 - 20x + 7