Question

find lim as x approaches pi/4:
(1-tanx)/(sinx-cosx)

Answer 1

it is in 0/0 form so we have to use l hospitals rule

Answer 2

do u know abt l hospital rule?

Answer 3

we did like one in class but i don't know how to use it well yet

Answer 4

ok u r given limit x tends to pi/4
so first step is to put pi/4 in the given eqn in place of x.first check numerator wat u get by putting it.

Answer 5

can u tell me wt will u get when u put pi/4 in place of x in numerator?

Answer 6

well it's 0 over 0 so we need to change it

Answer 7

i just haven't done limits in ages and i don't remember

Answer 8

have u undrstood how it is coming 0/0?

Answer 9

yes

Answer 10

Why not change tan x to sin x/cos x ...and simplify the expression? Then take the limit.

Answer 11

ok then,the next step is to differentiate numerator separety

Answer 12

its ur choice @Spidermonkeyy but u should also learn l hospitals rule.

Answer 13

i fu wnt i an explain the entire process to u.

Answer 14

differentiate as in -sec^2x?

Answer 15

yes please

Answer 16

yes good! now differentiate denominator and tell me wt u get

Answer 17

cos+sin?

Answer 18

yes good! now put the differentiated part in fraction