Recent questions tagged p36

Prove that $\tan^{-1}{\frac{1}{4}}+\tan^{-1}{\frac{2}{9}}=\sin^{-1}{\frac{1}{\sqrt 5}}$

asked Jul 9, 2014 by balaji.thirumalai

1 answer

If $2\tan^{-1}(\cos x)=\tan^{-1}(2cosecx)$,then show that $x=\Large {\frac{\pi}{4}}$

asked Jun 12, 2014 by balaji.thirumalai

1 answer

Using vector method prove that : $d)\;\cos (A+B)=\cos A\cos B+\sin A\sin B$

asked Apr 22, 2013 by sreemathi.v

1 answer

Using vector method prove that : $c)\;\cos (A+B)=\cos A\cos B-\sin A\sin B$

asked Apr 22, 2013 by sreemathi.v

1 answer

Using vector method prove that : $b)\;\sin (A-B)=\sin A\cos B-\cos A\sin B$

asked Apr 22, 2013 by sreemathi.v

1 answer

A small seminar hall can hold 100 chairs.Three different colours(red,blue and green) of chairs are available. The cost of a red chair is Rs.240, cost of a blue chair is Rs.260, and the cost of a green chair is Rs.300. The total cost of chair is Rs.25,000. Find atleast 3 different solution of the number of chairs in each colour to be purchased.

asked Mar 29, 2013 by poojasapani_1

1 answer

Solve the following non-homogeneous system of linear equation by determinant method: $\large \frac{1}{x}+\frac{2}{y}-\frac{1}{z}=1\;;\frac{2}{x}+\frac{4}{y}+\frac{1}{z}=5\;;\frac{3}{x}-\frac{2}{y}-\frac{2}{z}=0$

asked Mar 29, 2013 by poojasapani_1

1 answer

Find the simplified form of $cos^{-1}(\frac{3}{5}cos x+\frac{4}{5}sin x),$where $x\in (\frac{-3}{4},\frac{3}{4})$

asked Feb 19, 2013 by sreemathi.v

1 answer

Prove that $tan^{-1}\frac{\sqrt{1+x^2}+\sqrt{1-x^2}}{\sqrt{1+x^2}-\sqrt{1-x^2}}=\frac{\pi}{4}+\frac{1}{2}cos^{-1}x^2$

asked Feb 19, 2013 by sreemathi.v

1 answer

If a, b & c are the lengths of the sides of a triangle, using vector method, show that its area is $\sqrt {s(s-a)(s-b)(s-c)}$ where $2s=a+b+c$

asked Feb 5, 2013 by meena.p

1 answer

If D, E & F are the mid-points of the sides of a triangle ABC, prove by vector method that area of \[\bigtriangleup DEF=\frac{1}{4}(area\;of\;\bigtriangleup ABC).\]

asked Feb 5, 2013 by meena.p

0 answers

If a, b & c are the lengths of the sides opposite respectively to the angles A, B & C of a $\bigtriangleup ABC,$ using vector method show that \[a)\cos A=\frac{b^2+c^2-a^2}{2bc} \qquad b)\;a=b\cos C+c \cos B.\]

asked Feb 5, 2013 by meena.p

0 answers

Prove by vector method, that the parallelogram on the same base and between the same parallels are equal in area.

asked Feb 5, 2013 by meena.p

0 answers

Using vector method, show that the diagonals of a Rhombus bisect each other at right angles.

asked Feb 5, 2013 by meena.p

1 answer

Using vector method, prove that if two medians of a triangle are equal, then it is an isosceles.

asked Feb 5, 2013 by meena.p

1 answer

Using vector method, prove that if the diagonals of a parallelogram are equal in length, then it is a rectangle.

asked Feb 5, 2013 by meena.p

1 answer

Prove that the perpendicular bisectors of a triangle are concurrent.

asked Feb 5, 2013 by meena.p

1 answer

Prove that the altitudes of a triangle are concurrent.

asked Feb 5, 2013 by meena.p

1 answer

Using vector method, find the angle between two diagonals of a cube?

asked Feb 5, 2013 by meena.p

1 answer

Using vector method prove that : $a)\;\sin (A+B)=\sin A\cos B+\cos A\sin B$

asked Feb 5, 2013 by meena.p

1 answer