AP EAMCET · Maths · Indefinite Integration

$\int \frac{\sin α}{\sqrt{1 + \cos α}} d α =$

A $- 2 \sqrt{2} \cos (\frac{α}{2}) + c$
B $2 \sqrt{2} \cos (\frac{α}{2}) + c$
C $\sqrt{2} \cos (\frac{α}{2}) + c$
D $- \sqrt{2} \cos (\frac{α}{2}) + c$

Verified Solution

Answer & Solution

Correct Answer

(A) $- 2 \sqrt{2} \cos (\frac{α}{2}) + c$

Step-by-step Solution

Detailed explanation

∫sinα1+cosαdα Rationalize =∫sinα1-cosα1-cos2αdα =∫1-cosαdα Using cos2x=1-2sin2x, we get =∫1-1-2sin2α2dα =2∫sinα2dα =-22cosα2+c

Apply the relevant identity from the chapter and substitute the values established in the previous step, keeping the original constraint in view.

Use the simplified expression to isolate the unknown, then plug the result back into the question setup to confirm the working is internally consistent.

Cross-check against a boundary or limiting case. Both the dimensional balance and the qualitative behaviour at the extreme should agree with the candidate answer.

Combine the steps above to identify the correct option. The remaining choices each fail at least one of the consistency, dimensional, or boundary checks.

Same subject

If $\cos \alpha+\cos \beta=a$ and $\sin \alpha+\sin \beta=b$, then match the items given in List $-A$ with those of their values in List-B

List-A	Liat-B
(I) $\tan \left(\frac{\alpha+\beta}{2}\right)=$	(a) $\frac{ b }{ a }$
(II) $\cos (\alpha+\beta)=$	(b) $\frac{2 a b}{a^2+b^2}$
(III) $\sin (\alpha+\beta)^{-}$	(c) $\frac{2 a b}{a^2-b^2}$
(IV) $\tan (\alpha+\beta)=$	(d) $\frac{a^2-b^2}{a^2+b^2}$
	(e) $\frac{a^2+b^2}{a^2-b^2}$

AP EAMCET 2023 Medium

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From AP EAMCET

List - I (Type of reaction)	List - II (Final Product)
Reimer - Tiemann reaction
Etard reaction
Sandmeyer reaction
Friedel-Crafts reaction

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List-A	Liat-B
(I) \(\tan \left(\frac{\alpha+\beta}{2}\right)=\)	(a) \(\frac{ b }{ a }\)
(II) \(\cos (\alpha+\beta)=\)	(b) \(\frac{2 a b}{a^2+b^2}\)
(III) \(\sin (\alpha+\beta)^{-}\)	(c) \(\frac{2 a b}{a^2-b^2}\)
(IV) \(\tan (\alpha+\beta)=\)	(d) \(\frac{a^2-b^2}{a^2+b^2}\)
	(e) \(\frac{a^2+b^2}{a^2-b^2}\)

∫sinα1+cosαdα=

Step-by-step Solution

$\int \frac{\sin α}{\sqrt{1 + \cos α}} d α =$