TRIGONOMETRIC FUNCTIONS - CLASS XI FULL CHAPTER

The value of $\sin\left(45\degree+x\right)-\cos\left(45\degree-x\right)=$  

•  $2\cos x$  

•  $2\sin x$  

• 1

• 0

If $\sin x+\cos x=1,$  then $\sin2x=$  

• 1

• 1/2

• 0

• - 1

 $\frac{\left(2\tan^{ }15\degree\right)}{1+\tan^215\degree}=$  

• 1/2

• 0

• 1

• none of these

Value of $3\sin30\degree-4\sin^330\degree=$  

• 1

• 0

• 1/2

• none of these

 $\cos x\cos y+\sin x\sin y=$  

•  $\sin\left(x+y\right)$  

•  $\cos\left(x+y\right)$  

•  $\cos\left(x-y\right)$  

•  $\sin\left(x-y\right)$  

 $\cot\left(x-y\right)=$  

•  $\frac{\left(\cot x+\cot y\right)}{1-\cot x\cot y}$  

•  $\frac{\left(\cot x\cot y-1\right)}{\cot y+\cot x}$  

•  $\frac{\left(\cot x\cot y+1\right)}{\cot x-\cot y}$  

•  $\frac{\left(\cot x\cot y+1\right)}{\cot y-\cot x}$  

If $\cos x=-\frac{4}{5},\ where\ x\in III\ quad$ then  $\sin\left(\frac{x}{2}\right)=$   

•  $\frac{3}{\sqrt{10}}$  

•  $-\frac{3}{\sqrt{10}}$  

•  $\frac{1}{\sqrt{10}}$  

•  $-\frac{1}{\sqrt{10}}$