3. Given A(3,5), B(7, 10), C(0, 2), and D(1, a),
determine the value of a for which:
a) Line AB is parallel to line CD.
b) Line AB is perpendicular to line CD.
please help!! i’m failing grade 10 precal and i need this❤️ will give 15 points

Respuesta :

Answer:

1)  if Line AB is parallel to line CD then value of a is: a=3

2) if Line AB is perpendicular to line CD then value of a is: a=1

Step-by-step explanation:

We are given A(3,5), B(7, 10), C(0, 2), and D(1, a) we need to find value of a for which:

We can use slope formula: [tex]Slope=\frac{y_2-y_1}{x_2-x_1}[/tex] to find value of a according to conditions given.

We are given:

[tex]x_1=3, y_1=5, x_2=7, y_2=10 \ for \ line \ AB \ and \\\x_1=0, y_1=2, x_2=1, y_2=a \ for \ line \ CD \[/tex]

a) Line AB is parallel to line CD.

When 2 lines are parallel there slope is same so, using this we can find value of a

[tex]Slope \ of \ line \ AB = Slope \ of \ line \ CD[/tex]

[tex]\frac{y_2-y_1}{x_2-x_1}= \frac{y_2-y_1}{x_2-x_1}\\\frac{10-5}{7-3}=\frac{a-2}{1-0} \\\frac{5}{5}=\frac{a-2}{1}\\1=a-2\\a=1+2\\a=3[/tex]

So, if Line AB is parallel to line CD then value of a is: a=3

b) Line AB is perpendicular to line CD.

When 2 lines are perpendicular there slopes are opposite of each other so, using this we can find value of a

[tex]Slope \ of \ line \ AB =-\frac{1}{Slope \ of \ line \ CD}[/tex]

[tex]\frac{y_2-y_1}{x_2-x_1}=-\frac{1}{ \frac{y_2-y_1}{x_2-x_1}} \\\frac{y_2-y_1}{x_2-x_1}=-\frac{x_2-x_1}{y_2-y_1}\\\frac{10-5}{7-3}=-\frac{1-0}{a-2} \\\frac{5}{5}=-\frac{1}{a-2}\\1=-\frac{1}{a-2}\\a-2=-1\\a=-1+2\\a=1[/tex]

So, if Line AB is perpendicular to line CD then value of a is: a=1