In problems 3-6, find the slope msec of the se- cant line through the two given points and then calculate mtan = lim msec- h+0 3. f(x) = x2 (a) (-2, 4), ( -2 + h, (-2+1)2) (b) (0.5,0.25), (0.5 + h, (0.5 + h)2 ) 4. f(x) = 3+x2 (a) (1,4), (1 + h,3+ (1+h)?) b) (x,3+ x2), (x + h,3+ (x+h)?) 5. fx) =7x -x2 (1,6), (1 + h, 7(1 + h) - (1+h)2) (b) ( x, 7x - x2), (x + h, 7(x+ h) - (x+h)?)