Which expression is equivalent to cos (70°)? Cos ^-1 (20)

Sin ^-1 (20)

Cos (20)

Sin (20)

sin20°

Step-by-step explanation:

Using the cofunction identity

cosx = sin(90 - x) , thus

cos70° = sin(90 - 70)° = sin20°

solution:

→c= a b , that is product of a and b is possible only when when a is m × n matrix and b is n × p matrix.

that is, number of columns of a= number of rows of b.

so, size of matrix , c= a b is , if a = (m × n)matrix

b= (n × p)matrix

then a b = [ (m × n)matrix] ×[   (n × p)matrix ]

→→c= a b= [m × p ] matrix

→→size of product a b will be equal to = number of rows of a × number of columns of b