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Friends please help me out to solve this question

Physical Mathematics
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Bitthal Maheshwari
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    For elementary/homework/computation questions of this form, we generally ask that you show any progress you've made and you point out specifically where you are stuck. We want to help you understand the problem; we don't want to do your homework for you. – Physical Mathematics Apr 24 '20 at 23:14
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    Try with $A=\pi/2$ and $B=C=\pi/4$. – egreg Apr 24 '20 at 23:17
  • It is not my homework and I tried this question by applying row coloumn method but after applying row coloumn method I am getting a equation which I am not able to solve there I stuck. – Bitthal Maheshwari Apr 24 '20 at 23:37
  • @egreg Is this the right method to put values and solve? – Bitthal Maheshwari Apr 24 '20 at 23:39

1 Answers1

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Hint

Start with $R_2'=R_2-R_1, R_3'=R_3-R_1$

$$\cot B-\cot A=\dfrac{\sin(A-B)}{\sin A\sin B}$$

Using Prove $ \sin(A+B)\sin(A-B)=\sin^2A-\sin^2B $

$$\sin^2B-\sin^2A=-\sin(A+B)\sin(A-B)$$

Finally $A+B=\pi-C$

lab bhattacharjee
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