Let f (x) = 2x² - 7. After simplifying the difference quotient while using the defin ²+2xh+h²-2² (a.) f'(x) = lim 0 h (b.) f'(x) = lim- x² + 4xh +0 (c.) f'(x) = lim 0 4xh (d.) f'(x) = lim O a Ob Od - 0 4x + 2h