There are two families A and B. There are 4 men, 2 women and 1 child in family A
Chapter 3 Matrices Class 12 Maths
There are two families A and B. There are 4 men, 2 women and 1 child in family A and 2 men, 3 women and 2 children in family B. They recommended daily allowance for calories i.e. Men: 2000, Women: 1500, Children: 1200 and for proteins is Men: 50 gms., Women: 45 , Children: 30 gms. Represent the above information by matrices, using matrix multiplication calculate the total requirements of calories and proteins for each of the families.

Express the following matrices as the sum of symmetric and a skew symmetric matrix
Updated
October 2, 2022, 10:23 pm
Question 4. Express the following matrices as the sum of symmetric and a skew symmetric matrix: {\displaystyle {\begin{bmatrix} 2&{ - 2}&{ - 4}\\ { - 1}&3&4\\ 1&{ - 2}&{ - 3} \end{bmatrix}} }

Show that the matrix B′AB is symmetric or skew symmetric according
Updated
November 1, 2022, 5:14 am
NCERT Miscellaneous Exercise Question 5 : Show that the matrix B′AB is symmetric or skew symmetric according as A is symmetric or skew symmetric.

Show that AB is a zero matrix, provided θ − ϕ is an odd multiple of π over 2
Updated
September 16, 2022, 2:48 pm
Question 7. If {\displaystyle A = { \begin{bmatrix} {\cos^2\theta} & {\cos \theta \sin \theta} \\ {\cos \theta \sin \theta } & {\sin^2 \theta} \end{bmatrix} } } , {\displaystyle B = {\begin{bmatrix} {\cos^2 \phi} & { \cos \phi \sin \phi } \\ {\cos \phi \sin \phi } & {\sin^2 \phi } \end{bmatrix}} } then show that AB is a zero matrix, provided {\displaystyle (\theta - \phi )} is an odd multiple of {\displaystyle \frac{\pi }{2}} .