Prove that if `A=([2,3],[4,2])` then `A^(-1)=([-(1)/(4),(3)/(8)],[1/2,-(1)/4])`

If A=[(3,-3,4),(2,-3,4),(0,-1,1)] , then A^(-1)=

Prove that : tan^(-1)(1/2) + tan^(-1)(1/3) = tan^(-1)(3/5) + tan^(-1)(1/4) = pi/4

Prove that: 3cos^(-1)x=cos^(-1)(4x^3-3x), x in [1/2,1]

Prove that: (9pi)/8-9/4sin^(-1)1/3=9/4sin^(-1)(2sqrt(2))/3

Prove that : [4 + 3 sqrt(-20)]^((1)/(2)) + [4 -3 sqrt(-20)]^((1)/(2))= 6

Prove the following: tan^(-1)(1/4)+tan^(-1)(2/9)=1/2cos^(-1)(3/5)

Prove that: 3^(1/2)xx3^(1/4)xx3^(1/8)xx...=3

Prove that: (9pi)/8-9/4sin^(-1)(1/3)=9/4sin^(-1)((2sqrt(2))/3)

If A={1,2,3},B={3,4}and C={4,5,6}, "then prove that" (AxxB)uu(AxxC) ={(1,3),(1,4),(1,5),(1,6),(2,3),(2,4),(2,5 ),(2,6),(3,3),(3,4),(3,5),(3,6)}