If limit as delta x approaches 0 of tan(0+Δx)-tan(0)/Δx =1

Question

which of the following is false:

d/dx [tanx]=1
the slope of y = tan(x) at x = 0 is 1

y = tan(x) is continuous at x = 0

y = tan(x) is differentiable at x = 0

Answer 1

assuming those 0's should be x's

the first assertion is false. d/dx(tanx) = 1 at x=0, not everywhere.

Kind of an odd problem, since the last 3 statements are all obviously true.