How do you find the square root of an integer

Anyone know? will mark brainliest if correct

Atruck can be rented from company a $50 a day plus $0.60 per mile. company b charges $20 a day plus $0.80 per mile to rent the same truck. find the number of miles in a day at which the rental costs for company a and company b are the same

Given sin28.4=.4756, cos28.4=.8796, and tan28.4=.5407 find the cot of 61.6