When circle [tex]$P$[/tex] is plotted on a coordinate plane, the equation of the diameter that passes through point [tex]$Q$[/tex] on the circle is [tex]$y = 4x + 2$[/tex]. Which statement describes the equation of a line that is tangent to circle [tex]$P$[/tex] at point [tex]$Q$[/tex]?

A. The slope of the tangent line is [tex]$-4$[/tex].
B. The slope of the tangent line is [tex]$-\frac{1}{4}$[/tex].
C. The slope of the tangent line is [tex]$4$[/tex].
D. The slope of the tangent line is [tex]$\frac{1}{4}$[/tex].



Answer :

To determine the slope of the tangent line to circle [tex]\( P \)[/tex] at point [tex]\( Q \)[/tex], given that the equation of the diameter that passes through point [tex]\( Q \)[/tex] on the circle is [tex]\( y = 4x + 2 \)[/tex]:

1. Identify the slope of the diameter:
The equation of the diameter is given in the slope-intercept form [tex]\( y = mx + b \)[/tex], where [tex]\( m \)[/tex] represents the slope. In the equation [tex]\( y = 4x + 2 \)[/tex], the slope ([tex]\( m \)[/tex]) is 4.

2. Determine the slope of the tangent line:
The slope of the tangent line to a circle at a given point is the negative reciprocal of the slope of the diameter passing through that point. Therefore, the slope of the tangent line is the negative reciprocal of 4.

[tex]\[ \text{slope of tangent line} = -\frac{1}{4} \][/tex]

3. Select the correct statement:
We found that the slope of the tangent line is [tex]\(-\frac{1}{4}\)[/tex].

Therefore, the correct statement is:
B. The slope of the tangent line is [tex]\(-\frac{1}{4}\)[/tex].