`A B C` is a triangle. `D` is the mid point of `B Cdot` If `A D` is perpendicular to `A C ,` then prove that `cos A\ dotcos C=(2(c^2-a^2))/(3a c)` .

In any Delta ABC, prove that :a(b cos C-c cos B)=b^(2)-c^(2)

For any triangle ABC,prove that a(b cos C-c cos B)=b^(2)-c^(2)

A B C is a triangle. D is a point on A B such that A D=1/4A B and E is a point on A C such that A E=1/4A Cdot Prove that D E=1/4B Cdot

A B C is a triangle in which D is the mid-point of B C and E is the mid-point of A Ddot Prove that area of B E D=1/4a r e aof A B Cdot GIVEN : A A B C ,D is the mid-point of B C and E is the mid-point of the median A Ddot TO PROVE : a r( B E D)=1/4a r( A B C)dot

If in a triangle ABC, the altitude AM be the bisector of /_BAD , where D is the mid point of side BC, then prove that (b^2-c^2)= (a^2)/(2) .

A B C is a triangle. D is a point on A B such that D=1/4A B\ a n d\ E is a point on A C such that A E=1/4A Cdot Prove that D E=1/4B C

In any Delta ABC, prove that :a cos A+b cos B+c cos C=2a sin B sin C

If in a triangle ABC ,the altitude AM be the bisector of /_BAD, where D is the mid point of side BC, then prove that (b^(2)-c^(2))=a^(2)/2

If D is the mid-point of the side BC of triangle ABC and AD is perpendicular to AC, then 3b^(2)=a^(2)-c( b )3a^(2)=b^(2)3c^(2)b^(2)=a^(2)-c^(2)(d)a^(2)+b^(2)=5c^(2)

In any Delta ABC, prove that :(1+cos(A-B)cos C)/(1+cos(A-C)cos B)=(a^(2)+b^(2))/(a^(2)+c^(2))