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If sin theta + cos theta = m and sec th...

If ` sin theta + cos theta = m and sec theta + "cosec" theta = n, ` prove that
` n(m^(2)-1) = 2m. `

Text Solution

Verified by Experts

We have
` n(m^(2) -1) = ( sec theta + "cosec" theta )[( sin theta + cos theta)^(2) -1] `
` = ((1)/(cos theta) + (1)/(sin theta))[(sin^(2)theta + cos^(2)theta) + 2 sin theta cos theta -1 ] `
` =((sin theta + cos theta))/(sin theta cos theta) * 2 sin theta cos theta `
`=2(sin theta + cos theta)= 2m. `
Hence, `n(m^(2) -1) = 2m. `
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Knowledge Check

  • If sin theta + costheta = m and sin theta - cos theta = n , then

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    2
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    2n
    C
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