A product (that has not been yet invented) that involves lighting up when something happens?

An equation where variables are used to represent known values—function notation true or false

Which expression is equal to (f+g)(x)?

The construction of copying qpr is started below. the next step is to set the width of the compass to the length of ab. how does this step ensure that a new angle will be congruent to the original angle? by using compass take the measures of angle and draw the same arc according to it.