Given:
The equation of a circle is
A tangent line l to the circle touches the circle at point P(12,5).
To find:
The gradient of the line l.
Solution:
Slope formula: If a line passes through two points, then the slope of the line is
Endpoints of the radius are O(0,0) and P(12,5). So, the slope of radius is
We know that, the radius of a circle is always perpendicular to the tangent at the point of tangency.
Product of slopes of two perpendicular lines is always -1.
Let the slope of tangent line l is m. Then, the product of slopes of line l and radius is -1.
Therefore, the gradient or slope of the tangent line l is 
.
The <em>correct answers</em> are:
A) Both can be solved by graphing;
C) Both can be solved by substitution; and
D) Both have solutions at the points of intersection.
Explanation:
Just as a system of linear equations can be solved by graphing, a system of quadratic equations can as well. We graph both equations. We then look for the intersection points of the graphs; these intersection points will be the solutions to the system.
We can also solve the system by substitution. If we can get one variable isolated, we can substitute this into the other equation to solve.
Answer: 57.1 (rounded)
Step-by-step explanation:
Area of triangle formula: 1/2 x base x height
Area of a semicircle: 1/2 x pi x r^2
(1/2 x 8 x 8) + (1/2 x pi x 4^2)
= 57.1 (rounded)
Answer:
1 3/40
Step-by-step explanation:
1 1/4 +1 1/5 +7/8= 3 13/40
3/4 .3= 2 1/4
3 13/40 - 2 1/4
Answer:
Simple interest=$324 Total=2124
Step-by-step explanation:
Simple interest=6%
6% of 1800=108
108x3=324
1800+324=2124
