let's recall that the graph of a function passes the "vertical line test", however, that's not guarantee that its inverse will also be a function.
A function that has an inverse expression that is also a function, must be a one-to-one function, and thus it must not only pass the vertical line test, but also the horizontal line test.
Check the picture below, the left-side shows the function looping through up and down, it passes the vertical line test, in green, but it doesn't pass the horizontal line test.
now, check the picture on the right-side, if we just restrict its domain to be squeezed to only between [0 , π], it passes the horizontal line test, and thus with that constraint in place, it's a one-to-one function and thus its inverse is also a function, with that constraint in place, or namely with that constraint, cos(x) and cos⁻¹(x) are both functions.
Answer:
Opt A and D
Step-by-step explanation:
65% is 100 based number, this means that 65% is the same as 65/100, or 0,65.
65% of 20 is obtained performing the following operation:
0,65 * 20
or
65*20/100
Any of them
Answer:
Discrete; number of Months after the first year; amount remaining on the card.
Step-by-step explanation:
The value of the card strictly loses $2.50/month after the first year of purchase. This means that the values can only be $22.50, $20, etc. If it were continuous, it would lose an amount that led up to $2.50, meaning that you could have values such as $23.48 and $24.07. We cannot have these values, therefore the relationship is discrete.
As time passes, the amount of money in the card changes. As the amount of money in the card depends on the number of months, we can say that the number of months is the independent variable while the amount of money on the card is the dependent variable.
Hope this helps.
