Final answer:
To find the points on the graph of f(x) with horizontal tangent lines, we set the derivative equal to zero and solve for x. The points are (0,0) and (-1,1).
Step-by-step explanation:
To determine the points on the graph of f(x) at which the tangent line is horizontal, we need to find the values of x where the derivative of f(x) equals zero.
The derivative of f(x) = 6x⁷ + 7x⁶ is f'(x) = 42x⁶ + 42x⁵.
Setting f'(x) equal to zero and solving for x, we get:
42x⁶ + 42x⁵ = 0
Factoring out 42x⁵, we have:
42x⁵(x + 1) = 0
So, the values of x where the tangent line is horizontal are x = 0 and x = -1.
Therefore, the correct answer is (0,0) and (-1,1).