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In a triangle A B C ,a=4,b=3,/A=60^@ the...

In a triangle `A B C ,a=4,b=3,/_A=60^@` then `c` is root of the equation `c^2-3c-7=0` (b) `c^2+3c+7=0` (c) `c^2-3c+7=0` (d) `c^2+3c-7=0`

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Given,`a=4,b=3,∠A=60^@ `
Using cosine rule,
`cosA=(b^2+c^2−a^2)/(2bc) `
​ we have ⇒`1/2​=(9+c^2−16)/(6c)​ `
⇒`3c=9+c^2−16 `
⇒`c^2−3c−7=0 `
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