Question

lim x-->0 (1-cosx)/sin2x

Answer 1

do u know L hopital rule?

Answer 2

didn't know L hopital rule?

Answer 3

lim of sinax/x = a , same with cos...

lim 1-1+2sin^2(x/2) /sin2x

= 2 sin^2(x/2) / sin2x

2sin(x/2) * sin(x/2) /sin2x * x/x

2sin(x/2) sin(x/2)/x / sin2x/x

2sin(0) * 0.5 / 2 = 0

Answer 4

I doubt you can read that xD upside down.

Answer 5

i dosnt understand

Answer 6

Use half angle rule , you know it ?

cosx = 1- 2sin^2(x/2)

That way you will eliminate the 1.

Now divide over x in denominator and nominator

lim of sinax/x = a

so you will get 0.5 / 2 but you have sin^2 so you will replace one of them with 0