A binary operation is defined on the set R of real numbers by:
a*b=a+b + ab where a, bER
(i) Calculate 5*(-2)*5.
(ii) Find the identity element e of R
under the operation*
(iii) Determine the inverse under
general element aER and state
which element has no inverse

62.2

Step-by-step explanation:

Hello There!

we need to find the missing angle using law of cosines

The law of cosines formula for finding an angle is

Important note: c^2 = opposite side of missing angle

so we are given all of the measurements so all we need to do is plug in the values

so our last step would be to isolate the variable (x)

to do so we take the inverse of cos -^1(arccos) and multiply that by each side

then we would round to the nearest tenth and get that x = 62.2