true or false?

1. True and False (1] If a function fcan be expressed as f=g\"h, a multiplication of2 functions, g and h, then D(=D{g* h"D(g) +g"D(h] is always true. (2] If f is continuous over {a, b), then lim ffx) = L implies f[a)=L. xra 2 (3] For the function f(x) = 932 x2 , the slope of the tangent line at F2 is T. 5 {4] _For y = a\" g : xax'l. dx (5] If a function, fix}, has a root at x=a, then there always exist a small number .5 such that f(a E) and f(a + 5) have opposite sign {6] If the radius of a circle, r, is increasing with a rate of 1.5 ft/sec, then the area of the circle will be increasing as 3317'. I [3'] lff and g are continuous functions at x=a, then ffg is also a continuous function at x=a, if g(a) :5 D. I 05' (8] Given =,=U,' xi. __ y | XI it 5!\" (9] _ If f'lx} is continuous at x=a, then f\" must also be continuous at x=a. d . {10} s1n(x2) = cos(x2) dx