Let x and y be vectors in r3. prove that if x + yis
orthogonal to x - y then
x
=
y
. give a geometrical interpretation of this result.

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?

A25- foot ladder leans against a building and reaches a point of 23.5 feet above the ground .find the angle that the ladder makes with the building

Which value of y will make the inequality y< -1 false?