Find a ⋅ b. a = < 5, 2> , b = < 4, 5>

  30

Step-by-step explanation:

For a = <xa, ya> and b = <xb, yb>, the dot product is the sum of products ...

  a·b = (xa)(xb) + (ya)(yb)

Substituting the given information, you have ...

  a·b = 5·4 + 2·5 = 20 + 10

  a·b = 30

Some graphing calculators can do such math. There are also dot product calculators available on the Internet. If you have quite a few of these to calculate, you can put the appropriate formula into a spreadsheet.

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this