Commerce (English Medium) इयत्ता ११ - CBSE Question Bank Solutions

If A and B are two sets such that \[n \left( A \right) = 115, n \left( B \right) = 326, n \left( A - B \right) = 47,\] then write \[n \left( A \cup B \right)\] 

Prove that: tan (−225°) cot (−405°) −tan (−765°) cot (675°) = 0

The number of subsets of a set containing n elements is 

For any two sets A and B,\[A \cap \left( A \cup B \right) =\]

If A = {1, 3, 5, B} and B = {2, 4}, then 

Prove that: \[\tan\frac{11\pi}{3} - 2\sin\frac{4\pi}{6} - \frac{3}{4} {cosec}^2 \frac{\pi}{4} + 4 \cos^2 \frac{17\pi}{6} = \frac{3 - 4\sqrt{3}}{2}\]

Prove that:

Prove that:
\[\frac{\cos (2\pi + x) cosec (2\pi + x) \tan (\pi/2 + x)}{\sec(\pi/2 + x)\cos x \cot(\pi + x)} = 1\]

Prove that

If A = |1, 2, 3, 4, 5|, then the number of proper subsets of A is 

In set-builder method the null set is represented by

Prove that

Prove that

Prove that

Prove that:
\[\sin^2 \frac{\pi}{18} + \sin^2 \frac{\pi}{9} + \sin^2 \frac{7\pi}{18} + \sin^2 \frac{4\pi}{9} = 2\]

Prove that:
\[\sec\left( \frac{3\pi}{2} - x \right)\sec\left( x - \frac{5\pi}{2} \right) + \tan\left( \frac{5\pi}{2} + x \right)\tan\left( x - \frac{3\pi}{2} \right) = - 1 .\]

In a ∆ABC, prove that:
cos (A + B) + cos C = 0

In a ∆ABC, prove that:

In a ∆ABC, prove that: