Please help with problems 13,15,17,19 in pics.

Please show all work it's okay if handwritten.

11, 12, 13 and 14 Use the definition of continuity and the properties of limits to show that the function is continuous at the given number a. 11. f (x) = (x+ 2x3)4, a = -1 12. tz + 5t g ( t ) = 2t+ 1 , a = 2 13. p(v) = 2V302 + 1, a = 1 14. f (x) = 3x4 - 5x + Va2 + 4, a=2 15 and 16 Use the definition of continuity and the properties of limits to show that the function is continuous on the given interval. 15. f (ac) = ac + Vac - 4, [4, 00)17, 18, 19, 20, 21 and 22 Explain why the function is discontinuous at the given number a. Sketch the graph of the function. 17. f (2) = 1 a = -2 x + 2 Answer + 18. if x * -2 f (20 ) = a + 2 a = -2 1 if x = -2 19. 1 - 22 if x 1