सिद्ध कीजिए कि बिंदु `(-1,2,1),(1,-2,5),(4,-7,8)` और `(2,-3,4)` एक समांतर चतुर्भुज के शीर्ष है ।

Show that (-1,2,1),(1,-2,5),(4,-7,8) and(2,-3,4) are the vertices of parallelogram.

Verify the following : (-1, 2, 1), (1, -2, 5), (4, -7, 8) and (2, -3, 4) are the vertices of a parallelogram.

Verify the following: (-1,2,1) , (1,-2,5) , (4,-7,8) and (2,-3,4) are the vertices of a parllelogram.

Show that the points (-1,2,1), (1,-2,5), (4,-7,8) and (2,-3,4) are vertices of a parallelogram.

Verify the following: (-1,2,1),(1,-2,5),(4,-7,8) and (2,-3,4) are vertices of a parallelogram.

Show that the coplanar points (-1,2,1),(1,-2,5),(4,-7,8) and( 2,-3,4) are the vertices of a parallelogram.

Verify the following: (-1, 2, 1), (1, -2, 5), (4, -7, 8) and (2, -3, 4) are the vertices of a parallelogram.

Verify the following: (-1,2,1), (1,-2,5), (4,-7,8) and (2,-3,4) are vertices of a parallelogram.

सिद्ध कीजिए कि 2tan^(-1)sqrt((b)/(a))=cos^(-1)((a-b)/(a+b))