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sin(5*x)/(2*x)

Limit of the function sin(5*x)/(2*x)

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The solution

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     /sin(5*x)\
 lim |--------|
x->0+\  2*x   /
limx0+(sin(5x)2x)\lim_{x \to 0^+}\left(\frac{\sin{\left(5 x \right)}}{2 x}\right)
Limit(sin(5*x)/((2*x)), x, 0)
Detail solution
Let's take the limit
limx0+(sin(5x)2x)\lim_{x \to 0^+}\left(\frac{\sin{\left(5 x \right)}}{2 x}\right)
Do replacement
u=5xu = 5 x
then
limx0+(sin(5x)2x)=limu0+(5sin(u)2u)\lim_{x \to 0^+}\left(\frac{\sin{\left(5 x \right)}}{2 x}\right) = \lim_{u \to 0^+}\left(\frac{5 \sin{\left(u \right)}}{2 u}\right)
=
5limu0+(sin(u)u)2\frac{5 \lim_{u \to 0^+}\left(\frac{\sin{\left(u \right)}}{u}\right)}{2}
The limit
limu0+(sin(u)u)\lim_{u \to 0^+}\left(\frac{\sin{\left(u \right)}}{u}\right)
is first remarkable limit, is equal to 1.

The final answer:
limx0+(sin(5x)2x)=52\lim_{x \to 0^+}\left(\frac{\sin{\left(5 x \right)}}{2 x}\right) = \frac{5}{2}
Lopital's rule
We have indeterminateness of type
0/0,

i.e. limit for the numerator is
limx0+sin(5x)=0\lim_{x \to 0^+} \sin{\left(5 x \right)} = 0
and limit for the denominator is
limx0+(2x)=0\lim_{x \to 0^+}\left(2 x\right) = 0
Let's take derivatives of the numerator and denominator until we eliminate indeterninateness.
limx0+(sin(5x)2x)\lim_{x \to 0^+}\left(\frac{\sin{\left(5 x \right)}}{2 x}\right)
=
Let's transform the function under the limit a few
limx0+(sin(5x)2x)\lim_{x \to 0^+}\left(\frac{\sin{\left(5 x \right)}}{2 x}\right)
=
limx0+(ddxsin(5x)ddx2x)\lim_{x \to 0^+}\left(\frac{\frac{d}{d x} \sin{\left(5 x \right)}}{\frac{d}{d x} 2 x}\right)
=
limx0+(5cos(5x)2)\lim_{x \to 0^+}\left(\frac{5 \cos{\left(5 x \right)}}{2}\right)
=
limx0+52\lim_{x \to 0^+} \frac{5}{2}
=
limx0+52\lim_{x \to 0^+} \frac{5}{2}
=
52\frac{5}{2}
It can be seen that we have applied Lopital's rule (we have taken derivatives with respect to the numerator and denominator) 1 time(s)
The graph
02468-8-6-4-2-10105-5
One‐sided limits [src]
     /sin(5*x)\
 lim |--------|
x->0+\  2*x   /
limx0+(sin(5x)2x)\lim_{x \to 0^+}\left(\frac{\sin{\left(5 x \right)}}{2 x}\right)
5/2
52\frac{5}{2}
= 2.5
     /sin(5*x)\
 lim |--------|
x->0-\  2*x   /
limx0(sin(5x)2x)\lim_{x \to 0^-}\left(\frac{\sin{\left(5 x \right)}}{2 x}\right)
5/2
52\frac{5}{2}
= 2.5
= 2.5
Rapid solution [src]
5/2
52\frac{5}{2}
Other limits x→0, -oo, +oo, 1
limx0(sin(5x)2x)=52\lim_{x \to 0^-}\left(\frac{\sin{\left(5 x \right)}}{2 x}\right) = \frac{5}{2}
More at x→0 from the left
limx0+(sin(5x)2x)=52\lim_{x \to 0^+}\left(\frac{\sin{\left(5 x \right)}}{2 x}\right) = \frac{5}{2}
limx(sin(5x)2x)=0\lim_{x \to \infty}\left(\frac{\sin{\left(5 x \right)}}{2 x}\right) = 0
More at x→oo
limx1(sin(5x)2x)=sin(5)2\lim_{x \to 1^-}\left(\frac{\sin{\left(5 x \right)}}{2 x}\right) = \frac{\sin{\left(5 \right)}}{2}
More at x→1 from the left
limx1+(sin(5x)2x)=sin(5)2\lim_{x \to 1^+}\left(\frac{\sin{\left(5 x \right)}}{2 x}\right) = \frac{\sin{\left(5 \right)}}{2}
More at x→1 from the right
limx(sin(5x)2x)=0\lim_{x \to -\infty}\left(\frac{\sin{\left(5 x \right)}}{2 x}\right) = 0
More at x→-oo
Numerical answer [src]
2.5
2.5
The graph
Limit of the function sin(5*x)/(2*x)