- #1
grace77
- 43
- 0
The problem statement
What is the limit of sin2x/x as x approaches 0?Revelant equations
lim sin(x)/x = 1 x-->0
Attempt at a solution
so sin2x/x = 2sin(2x)/2x since sin(2x)/2x = 1 2sin(2x)/2x = 2*1
I know how to solve it this way however my teacher said you can solve it using double angle identity.
Sin2x= 2sinxcosx
That would be equal to lim2sinx/x * cosx/x
2sinx/x=2 but what would cos x/x when x approaches zero.. isn't that undefined? How do you figure that out then?
What is the limit of sin2x/x as x approaches 0?Revelant equations
lim sin(x)/x = 1 x-->0
Attempt at a solution
so sin2x/x = 2sin(2x)/2x since sin(2x)/2x = 1 2sin(2x)/2x = 2*1
I know how to solve it this way however my teacher said you can solve it using double angle identity.
Sin2x= 2sinxcosx
That would be equal to lim2sinx/x * cosx/x
2sinx/x=2 but what would cos x/x when x approaches zero.. isn't that undefined? How do you figure that out then?