B. Find the derivative of each function using the definition of derivatives. 1. y = x2 - 7x 2. y = 2x2 + 3x-1 C. Find the slope and the equation of the tangent line to the curve. 1. y = 3x - 9 at P(2, -3) 2. y = x2 +4 at x = -2 3. y= x2 - x+3 atx=1