If A = a cosec θ + bcot θ and B = a cot θ + b cosec θ, then what is the value of $A^2 - B^2 $ ? |
ab (a + b) $(a^2 - b^2)$ (a - b) |
$(a^2 - b^2)$ |
We are given that :- A = a cosec θ + bcot θ and B = a cot θ + b cosec θ Now, A² - B² = ( a cosec θ + bcot θ )² - ( a cot θ + bcosec θ )² = a² cosec² θ + b²cot² θ + 2 ab cosec θ . bcot θ - a² cot² θ - b²cosec² θ - 2 ab cosec θ . bcot θ = a² cosec² θ + b²cot² θ - a² cot² θ - b²cosec² θ = a² ( cosec² θ - cot² θ ) + b² ( cot² θ - cosec² θ ) { using , cosec² θ - cot² θ = 1 } = a² ( 1 ) + b² ( - 1 ) = a² - b²
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