Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions

Evaluate the following integral:

Evaluate the following integral:

Evaluate the following integral:

Evaluate the following integral:

Evaluate the following integral:

Evaluate 

\[\int\limits_0^\pi \frac{x}{1 + \sin \alpha \sin x}dx\]

Evaluate the following integral:

Evaluate the following integral:

Evaluate : 

In a triangle OAB,\[\angle\]AOB = 90º. If P and Q are points of trisection of AB, prove that \[{OP}^2 + {OQ}^2 = \frac{5}{9} {AB}^2\]

Prove that: If the diagonals of a quadrilateral bisect each other at right angles, then it is a rhombus. 

(Pythagoras's Theorem) Prove by vector method that in a right angled triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides. 

Prove by vector method that the sum of the squares of the diagonals of a parallelogram is equal to the sum of the squares of its sides.

Prove using vectors: The quadrilateral obtained by joining mid-points of adjacent sides of a rectangle is a rhombus. 

Prove that the diagonals of a rhombus are perpendicular bisectors of each other. 

Prove that the diagonals of a rectangle are perpendicular if and only if the rectangle is a square. 

If AD is the median of ∆ABC, using vectors, prove that \[{AB}^2 + {AC}^2 = 2\left( {AD}^2 + {CD}^2 \right)\] 

If the median to the base of a triangle is perpendicular to the base, then triangle is isosceles. 

In a quadrilateral ABCD, prove that \[{AB}^2 + {BC}^2 + {CD}^2 + {DA}^2 = {AC}^2 + {BD}^2 + 4 {PQ}^2\] where P and Q are middle points of diagonals AC and BD. 

Evaluate: `int_-π^π (1 - "x"^2) sin "x" cos^2 "x"  d"x"`.