Step-by-step explanation:
tan(-300) = tan(-300+360) = tan (60)
here we added 360 degree. where by adding 360 +or- (n×360) to the any angle nothing will change as they called equivalent angles
equivalent angles is by adding +or- n×360 to any angle is equivalent to that angle so tan(-300) = tan(60) then we will calculate tan(60) on the calculator