Mathematics
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OpenStudy (anonymous):
Suppose that triangle ABC has m< C = 90o, AC = 7 and AB = 9. Find cot(A) and csc(B).
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OpenStudy (anonymous):
you need the other side, which you find by pythagoras
\[7^2+(BC)^2=9^2\]
\[BC=\sqrt{9^2-7^2}=\sqrt{81-49}=\sqrt{32}=4\sqrt{2}\]
OpenStudy (anonymous):
SOH CAH TOA
OpenStudy (anonymous):
\[\cot(A) = \frac{7}{4\sqrt{2}}\] because it is adjacent over opposite
OpenStudy (anonymous):
find cb my pythagoras theorem
u get cb=root of 32=4 root 2
now cot A=7/4 root 2
cosec b=9/7
OpenStudy (anonymous):
and \[csc(B)= \frac{9}{7}\] because it is hypotenuse over opposite
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OpenStudy (anonymous):
what neel said
OpenStudy (anonymous):
i cant get u wat ur askin ????
OpenStudy (anonymous):
Sat are you sre for cot (A)?
OpenStudy (anonymous):
isn't it (7/8)(sqrt2)
OpenStudy (anonymous):
no my friend.
root 32=root of 16*2
which equals 4root 2
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OpenStudy (anonymous):
r u geting it ?????
OpenStudy (anonymous):
yup. thanks!
OpenStudy (anonymous):
most welcum
OpenStudy (anonymous):
just wasnt one of my answer options
OpenStudy (anonymous):
ok....
dont go on options be syre of ur method......
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OpenStudy (anonymous):
OpenStudy (anonymous):
sorry friend
m not able to see th attachment
OpenStudy (anonymous):
ok: here the options
OpenStudy (anonymous):
a) cot =(7/8) sqrt 2, csc 9/7)
OpenStudy (anonymous):
b) cot = 9/7, csc = (4/7) sqrt2
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OpenStudy (anonymous):
c) cot = (9/8) sqrt2, csc = 7/9
OpenStudy (anonymous):
d) cot = sqrt130, csc = (1/8)sqrt2
OpenStudy (anonymous):
e) cot + 4sqrt2, csc = 9sqrt130
OpenStudy (anonymous):
option A
OpenStudy (anonymous):
a
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OpenStudy (anonymous):
we wrote
\[\cot(A)=\frac{7}{4\sqrt{2}}\]
OpenStudy (anonymous):
oh, i see the diff
OpenStudy (anonymous):
if you multiply top and bottom by
\[\sqrt{2}\] you get
\[\frac{7\sqrt{2}}{8}\]
OpenStudy (anonymous):
i had A - so yay! thanks
OpenStudy (anonymous):
yeah just did that
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OpenStudy (anonymous):
some people don't like radicals in the denominator, so you get rid of them