In three dimensions, the cross product of two vectors is defined as shown below

Then, solving the determinant

In our case,

Where we used the formula for AxB to calculate ixj.
Finally,

Thus, (i+j)x(ixj)=i-j
Answer:
114
Step-by-step explanation:
break apart the shape into 2 smaller shapes and you'll get 15 and 4 for the 1st shape multiply them and you'll get 60. Then for the second shape you'll get 6 and 9 multiply them and you'll get 54. Last add them together and you get 114. (Sorry if I get it wrong)
Cos^4(x) =
(cos²x)² =
(1-sen²x)² =
1² - 2*1*sen²x + sen^4x =
1 - 2sen²x + sen^4x
x*x=152
x2=152
Take square root.
x=±√152
x=√238
or
x=−√238