A solid metal sphere with diameter 4cm needs to be covered with a protective material which costs £0.23 per cm2.
How much will it cost to cover the sphere with the material?
Give your answer rounded to 2 DP.

please help

1. 0.3 •4 is the same as 4 groups of 0.32. 7•0.8 is the same as 7 groups of 0.83. it increases by 0.5 every time, so 0.5x4 it increases by 0.9 every time, so 0.9x5. 0.9•12=10.86. 0.47•5=2.35i can finish the next ones in a separate post

Sin(a)+cos(a)+cot(a)-1=2(csc(x)+1)