Which expression is equivalent to 1+1/y/1-1/y

Find parametric equations for the line tangent to the curve of intersection of the surfaces at the given point. surfaces: xsquared2plus+2yplus+2zequals=1212 yequals=33 point: left parenthesis 1 comma 3 comma five halves right parenthesis

In the 30-60-90 triangle below side s has a length of and side r has a length

What is the missing reason in the proof? segment addition congruent segments theorem transitive property of equality subtraction property of equality?