Question

lim as x approaches 0 of (sinx)(tanx)(secx)/x^2?

Answer 1

sin*sec = tan
this can be rewritten as tan^2 /x^2

Answer 2

do you know L'hopitals rule?

Answer 3

no i dont!

Answer 4

answer is 1..i think so
since lim x-->0 (tan x)/x and lim x-->0 (sin x)/x are equal to one
and sec(0) = 1

Answer 5

@dumbcow ..no need for L'hopitals rule...just basic limit rules..

Answer 6

oh yeah, forgot about rearranging it into separate limits:)
sorry

Answer 7

sorry guys, that didnt help. my teacher wrote his answer as (sin^2x/x^2)(1/cosx)(secx)

Answer 8

and said each of those is equal to 1

Answer 9

wat ur teacher said is wat we discussed!!!lim x-->0 sin^2x/x^2 is also equal to one the same way as lim x-->0 sinx/x is equal to one..and cos(0) and sec(0) are also one.

Answer 10

how do you figure out by looking at the unit circle what sec(0) is?

Answer 11

If u consider a cosine wave....it starts from value 1 at 0 degree angle and the unit circle it starts from y-axis(90 degrees phase shift from origin-from the second quarter) and secant is reciprocal of cosine so...
u can realize this principle by using a right angled triangle also...