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OpenStudy (anonymous):
\[\lim_{x \rightarrow 0} \frac{ \sin7x }{ 4x }\]
OpenStudy (anonymous):
\[\lim_{x \rightarrow 0} \frac{ 4 }{ 7 }( \frac{ \sin x }{ x })\]
OpenStudy (anonymous):
\[\frac{ 4 }{ 7 }\lim_{x \rightarrow 0} \frac{ \sin x }{ x }\]
OpenStudy (anonymous):
sin x/x is just 1 and 4/7 times 1 is just 4/7
OpenStudy (anonymous):
done?
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OpenStudy (anonymous):
\[\lim_{x\to0}\frac{\sin ax}{ax}=1\]
So,
\[\lim_{x\to0}\frac{\sin7x}{4x}=\frac{7}{7}\lim_{x\to0}\frac{\sin7x}{4x}=\frac{7}{4}\lim_{x\to0}\frac{\sin 7x}{7x}=\cdots \]
OpenStudy (anonymous):
The answer should be the reciprocal of what you got: 7/4.
OpenStudy (anonymous):
haha yes, ofcourse, typo there. i meants 7/4
OpenStudy (anonymous):
meant*
OpenStudy (anonymous):
so
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OpenStudy (anonymous):
\[\lim_{x \rightarrow 0} \frac{ 7 }{ 4 }( \frac{ \sin x }{ x })\]
OpenStudy (anonymous):
\[\frac{ 7 }{ 4 }\lim_{x \rightarrow 0} \frac{ \sin x }{ x }\]
OpenStudy (anonymous):
= 7/4
OpenStudy (anonymous):
No, multiply by 7/7 (=1) and then switch out the 4x for 7x, then the sin7x or 7x turns into one. 1 times 7/4 will be 7/4. You got the right answer, but in the wrong way.