Math, asked by vikasbasa511, 1 year ago

if sec theta = square root of p^2+q^2/q find p sin theta-q cos theta/p sin theta + q cos theta

Answers

Answered by MaheswariS
45

\textbf{Given:}

sec\theta=\frac{\sqrt{p^2+q^2}}{q}

\textbf{To find:}

\text{The value of}\;\;\dfrac{p\:sin\theta-q\:cos\theta}{p\:sin\theta+q\:cos\theta}

sec\theta=\frac{\sqrt{p^2+q^2}}{q}

\text{Taking reciprocals, we get}

cos\theta=\dfrac{q}{\sqrt{p^2+q^2}}

\text{We know that}

\boxed{\bf\;sin^2\theta=1-cos^2\theta}

sin^2\theta=1-\frac{q^2}{p^2+q^2}

sin^2\theta=\frac{p^2+q^2-q^2}{p^2+q^2}

sin^2\theta=\frac{p^2}{p^2+q^2}

\implies\bf\:sin\theta=\frac{p}{\sqrt{p^2+q^2}}

\text{Now,}

\dfrac{p\:sin\theta-q\:cos\theta}{p\:sin\theta-q\:cos\theta}

=\dfrac{p(\frac{p}{\sqrt{p^2+q^2}})-q(\frac{q}{\sqrt{p^2+q^2}})}{p(\frac{p}{\sqrt{p^2+q^2}})+q(\frac{q}{\sqrt{p^2+q^2}})}

=\dfrac{\frac{p^2}{\sqrt{p^2+q^2}}-\frac{q^2}{\sqrt{p^2+q^2}}}{\frac{p^2}{\sqrt{p^2+q^2}}+\frac{q^2}{\sqrt{p^2+q^2}}}

=\dfrac{\frac{p^2-q^2}{\sqrt{p^2+q^2}}}{\frac{p^2+q^2}{\sqrt{p^2+q^2}}}

=\dfrac{p^2-q^2}{p^2+q^2}

\therefore\boxed{\bf\dfrac{p\:sin\theta-q\:cos\theta}{p\:sin\theta+q\:cos\theta}=\dfrac{p^2-q^2}{p^2+q^2}}

Find more:

If cot theta =q/p, show that (p sin theta -q cos theta /p sin theta +q cos theta )=(p^2-q^2/p^2+q^2){by taking a constant term}

https://brainly.in/question/9621837

Answered by bhavsardhruvn12
0

\textbf{Given:}Given:

sec\theta=\frac{\sqrt{p^2+q^2}}{q}secθ=

q

p

2

+q

2

\textbf{To find:}To find:

\text{The value of}\;\;\dfrac{p\:sin\theta-q\:cos\theta}{p\:sin\theta+q\:cos\theta}The value of

psinθ+qcosθ

psinθ−qcosθ

sec\theta=\frac{\sqrt{p^2+q^2}}{q}secθ=

q

p

2

+q

2

\text{Taking reciprocals, we get}Taking reciprocals, we get

cos\theta=\dfrac{q}{\sqrt{p^2+q^2}}cosθ=

p

2

+q

2

q

\text{We know that}We know that

\boxed{\bf\;sin^2\theta=1-cos^2\theta}

sin

2

θ=1−cos

2

θ

sin^2\theta=1-\frac{q^2}{p^2+q^2}sin

2

θ=1−

p

2

+q

2

q

2

sin^2\theta=\frac{p^2+q^2-q^2}{p^2+q^2}sin

2

θ=

p

2

+q

2

p

2

+q

2

−q

2

sin^2\theta=\frac{p^2}{p^2+q^2}sin

2

θ=

p

2

+q

2

p

2

\implies\bf\:sin\theta=\frac{p}{\sqrt{p^2+q^2}}⟹sinθ=

p

2

+q

2

p

\text{Now,}Now,

\dfrac{p\:sin\theta-q\:cos\theta}{p\:sin\theta-q\:cos\theta}

psinθ−qcosθ

psinθ−qcosθ

=\dfrac{p(\frac{p}{\sqrt{p^2+q^2}})-q(\frac{q}{\sqrt{p^2+q^2}})}{p(\frac{p}{\sqrt{p^2+q^2}})+q(\frac{q}{\sqrt{p^2+q^2}})}=

p(

p

2

+q

2

p

)+q(

p

2

+q

2

q

)

p(

p

2

+q

2

p

)−q(

p

2

+q

2

q

)

=\dfrac{\frac{p^2}{\sqrt{p^2+q^2}}-\frac{q^2}{\sqrt{p^2+q^2}}}{\frac{p^2}{\sqrt{p^2+q^2}}+\frac{q^2}{\sqrt{p^2+q^2}}}=

p

2

+q

2

p

2

+

p

2

+q

2

q

2

p

2

+q

2

p

2

p

2

+q

2

q

2

=\dfrac{\frac{p^2-q^2}{\sqrt{p^2+q^2}}}{\frac{p^2+q^2}{\sqrt{p^2+q^2}}}=

p

2

+q

2

p

2

+q

2

p

2

+q

2

p

2

−q

2

=\dfrac{p^2-q^2}{p^2+q^2}=

p

2

+q

2

p

2

−q

2

\therefore\boxed{\bf\dfrac{p\:sin\theta-q\:cos\theta}{p\:sin\theta+q\:cos\theta}=\dfrac{p^2-q^2}{p^2+q^2}}∴

psinθ+qcosθ

psinθ−qcosθ

=

p

2

+q

2

p

2

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