Is the sum of 4.2 and the square root of 2 rational or irrational

The given expression is irrational.

Step-by-step explanation:

We have been given an expression  

And we need to tell whether it is rational or irrational

Irrational numbers are those numbers which we can not write in simple fraction form

Rational numbers are those which can be written in fraction form both numerator and denominator should be integers.

The given expression can not be written in the form of simple fraction  and hence, the given expression is irrational.

(sin 42)/31. = sinx)/37

sinx = 37 (sin42)/31

= 37× 0.66/31 = 0.787

x= 51.9

other angle opposite to y = 180-51.9-42

= 180- 93.9 =86.1

so

sin42)/31 = sin 86.1)/y

0.021 = 0.997 /y

y= 0.997/0.021 =47.47