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sin(3*x)/(7*x)

Limit of the function sin(3*x)/(7*x)

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The solution

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     /sin(3*x)\
 lim |--------|
x->0+\  7*x   /
$$\lim_{x \to 0^+}\left(\frac{\sin{\left(3 x \right)}}{7 x}\right)$$
Limit(sin(3*x)/((7*x)), x, 0)
Detail solution
Let's take the limit
$$\lim_{x \to 0^+}\left(\frac{\sin{\left(3 x \right)}}{7 x}\right)$$
Do replacement
$$u = 3 x$$
then
$$\lim_{x \to 0^+}\left(\frac{\sin{\left(3 x \right)}}{7 x}\right) = \lim_{u \to 0^+}\left(\frac{3 \sin{\left(u \right)}}{7 u}\right)$$
=
$$\frac{3 \lim_{u \to 0^+}\left(\frac{\sin{\left(u \right)}}{u}\right)}{7}$$
The limit
$$\lim_{u \to 0^+}\left(\frac{\sin{\left(u \right)}}{u}\right)$$
is first remarkable limit, is equal to 1.

The final answer:
$$\lim_{x \to 0^+}\left(\frac{\sin{\left(3 x \right)}}{7 x}\right) = \frac{3}{7}$$
Lopital's rule
We have indeterminateness of type
0/0,

i.e. limit for the numerator is
$$\lim_{x \to 0^+} \sin{\left(3 x \right)} = 0$$
and limit for the denominator is
$$\lim_{x \to 0^+}\left(7 x\right) = 0$$
Let's take derivatives of the numerator and denominator until we eliminate indeterninateness.
$$\lim_{x \to 0^+}\left(\frac{\sin{\left(3 x \right)}}{7 x}\right)$$
=
Let's transform the function under the limit a few
$$\lim_{x \to 0^+}\left(\frac{\sin{\left(3 x \right)}}{7 x}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{\frac{d}{d x} \sin{\left(3 x \right)}}{\frac{d}{d x} 7 x}\right)$$
=
$$\lim_{x \to 0^+}\left(\frac{3 \cos{\left(3 x \right)}}{7}\right)$$
=
$$\lim_{x \to 0^+} \frac{3}{7}$$
=
$$\lim_{x \to 0^+} \frac{3}{7}$$
=
$$\frac{3}{7}$$
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
Rapid solution [src]
3/7
$$\frac{3}{7}$$
Other limits x→0, -oo, +oo, 1
$$\lim_{x \to 0^-}\left(\frac{\sin{\left(3 x \right)}}{7 x}\right) = \frac{3}{7}$$
More at x→0 from the left
$$\lim_{x \to 0^+}\left(\frac{\sin{\left(3 x \right)}}{7 x}\right) = \frac{3}{7}$$
$$\lim_{x \to \infty}\left(\frac{\sin{\left(3 x \right)}}{7 x}\right) = 0$$
More at x→oo
$$\lim_{x \to 1^-}\left(\frac{\sin{\left(3 x \right)}}{7 x}\right) = \frac{\sin{\left(3 \right)}}{7}$$
More at x→1 from the left
$$\lim_{x \to 1^+}\left(\frac{\sin{\left(3 x \right)}}{7 x}\right) = \frac{\sin{\left(3 \right)}}{7}$$
More at x→1 from the right
$$\lim_{x \to -\infty}\left(\frac{\sin{\left(3 x \right)}}{7 x}\right) = 0$$
More at x→-oo
One‐sided limits [src]
     /sin(3*x)\
 lim |--------|
x->0+\  7*x   /
$$\lim_{x \to 0^+}\left(\frac{\sin{\left(3 x \right)}}{7 x}\right)$$
3/7
$$\frac{3}{7}$$
= 0.428571428571429
     /sin(3*x)\
 lim |--------|
x->0-\  7*x   /
$$\lim_{x \to 0^-}\left(\frac{\sin{\left(3 x \right)}}{7 x}\right)$$
3/7
$$\frac{3}{7}$$
= 0.428571428571429
= 0.428571428571429
Numerical answer [src]
0.428571428571429
0.428571428571429
The graph
Limit of the function sin(3*x)/(7*x)