i would like help i this math question

Question

i need help on a debatably easy math question that for whatever reason i cant seem to find the answer of. the problem in question is 1 over the square root of 40.

Answer 1

1/sqr40 = 1/2sqr10

Often rationalizing the denominator is the problem. Multiply both numerator and denominator by sqr10 to get sqr10/20 = (1/20)sqr10 or 0.05sqr10

= about 0.158

sqr40/40 = 0.158 = 1/sqr40