Optional Mathematics X LSA

Sin(A+B) =

• CosBSinA + CosASinB

• SinBCosA + CosBSinA

• CosACosB - SinASinB

• None of these

Cos(A-B) =

• CosACosB + SinASinB

• —CosACosB + SinASinB

• CosACosB - SinASinB

• SinACosB - CosASinB

cot(A+B) =

• $\frac{\cot A\cot B-1}{\cot A+\cot B}$

• $\frac{\cot A\cot B+1}{\cot A-\cot B}$

• $\frac{\cot A\cot B-1}{\cot B-\cot A}$

• NONE OF THESE
  
  

1+Cos14x

• $\cos^27x$

• $2\cos^27x$

• $2\sin^214x$

• $\sin^23x$

 $\sin3\theta\ =$  

•  $4\sin^3\theta-3\sin\theta$  

•  $3\sin\theta+4\sin^3\theta$  

•  $3\sin\theta-4\sin^3\theta$  

•  $4\sin^3\theta+3\sin\theta$  

 $\cos3\theta\ =$  

•  $4\cos^3\theta+3\sin\theta$  

•  $4\cos^3\theta-3\cos\theta$  

•  $3\cos\theta-4\cos^3\theta$  

•  $3\cos^3\theta-4\cos\theta$  

 $\sec\left(270\degree-\theta\right)\ =$  

•  $\sec\theta$  

•  $\operatorname{cosec}\theta$  

•  $-\sec\theta$  

•  $-\operatorname{cosec}\theta$  

 $\sin2\alpha=$  

•  $\frac{2\tan\alpha}{1-\tan^2\alpha}$  

•  $\frac{2\tan\alpha}{1+\tan^2\alpha}$  

•  $\frac{1+\tan^2\alpha}{1-\tan^2\alpha}$  

•  $\frac{1-\tan^2\alpha}{1+\tan^2\alpha}$  

 $\sqrt{\frac{1-\cos2\theta}{1+\cos2\theta}}\ =$  

•  $\cot\theta$  

•  $\tan\theta$  

•  $\sin\theta$  

•  $\cos\theta$  

The value of cos (690^o) is

• -0.707

• -0.866

• 0.866

• -0.5