Two lines are if one is vertical and the other is horizontal or the slopes of the lines are negative reciprocals of each other

Then these two lines are perpendicular.

Step-by-step explanation:

The definition of perpendicular lines are that they have negative and reciprocal slopes. Therefore, these two lines would fit this definition and would be perpendicular.

a4 - 3a2 - 1

step-by-step explanation:

step   1   :

equation at the end of step   1   :

  ((a4) -   3a2) -   1

step   2   :

trying to factor by splitting the middle term

2.1     factoring   a4-3a2-1  

the first term is,   a4   its coefficient is   1 .

the middle term is,   -3a2   its coefficient is   -3 .

the last term, "the constant", is   -1