A shoreline is eroding at a rate of 1/3 foot per 3 months . How many feet are eroding per year?
1 answer:
You might be interested in
Given:
The function is:
To find:
The steps of finding the inverse function .
Solution:
We have,
The steps of finding the inverse function are:
Step 1: Substitute .
Step 2: Interchange x and y.
Step 3: Taking square on both sides, we get
Step 4: Adding 21 on both sides, we get
Step 5: Divide both sides by 7.
Step 6: Substitute .
, where
.
Therefore, the inverse of the given function is and the arrangement of steps is shown above.
Question 14, Part (i)
Focus on quadrilateral ABCD. The interior angles add to 360 (this is true for any quadrilateral), so,
A+B+C+D = 360
A+90+C+90 = 360
A+C+180 = 360
A+C = 360-180
A+C = 180
Since angles A and C add to 180, this shows they are supplementary. This is the same as saying angles 2 and 3 are supplementary.
==================================================
Question 14, Part (ii)
Let
x = measure of angle 1
y = measure of angle 2
z = measure of angle 3
Back in part (i) above, we showed that y + z = 180
Note that angles 1 and 2 are adjacent to form a straight line, so we can say
x+y = 180
-------
We have the two equations x+y = 180 and y+z = 180 to form this system of equations
Which is really the same as this system
The 0s help align the y terms up. Subtracting straight down leads to the equation x-z = 0 and we can solve to get x = z. Therefore showing that angle 1 and angle 3 are congruent. We could also use the substitution rule to end up with x = z as well.