General Math Flashcards
When solving an equation with a square root, why must you include the plus-minus sign?
The square root of a number can be both positive and negative, so you must include ± to capture both solutions.
Why is it important to only pick one value when using the square root in a function?
If you include both the positive and negative values, it would not pass the vertical line test, so it wouldn’t be a function.
What’s the common mistake when factoring quadratic expressions?
Forgetting to check for a common factor before using other factoring methods.
What is a common mistake when working with rational functions?
Forgetting to exclude values that make the denominator zero (vertical asymptotes).
Why is it incorrect to cancel terms in a rational function before factoring?
Cancelling before factoring can remove terms that could reveal critical values like holes in the graph.
Why should you be careful with the domain when dealing with logarithms?
Logarithms are undefined for non-positive numbers, so the domain must be restricted to positive values.
What is the error when simplifying a power of a function inside a radical?
Forgetting to use absolute value when taking even roots of an expression with an even power.
What’s a common mistake when solving exponential equations?
Forgetting to use logarithms to solve when the bases are different.
Why must you be cautious with absolute value functions when solving equations?
You must split the equation into two cases, one where the expression inside the absolute value is positive and one where it is negative.
What is the mistake people make with inverse functions?
People often forget to swap the x and y variables when solving for the inverse.
What’s a tricky aspect of finding the inverse of a function?
Forgetting to restrict the domain so that the inverse is also a function (if the original function is not one-to-one).
What do students often forget when graphing piecewise functions?
Forgetting to indicate whether the endpoints are open or closed based on the inequality symbols.
Why is it important to pay attention to the horizontal asymptotes in rational functions?
Students often forget that the horizontal asymptote shows the end behavior but can be crossed in the middle of the graph.
What’s a common error when working with transformations of functions?
Forgetting to apply horizontal stretches and compressions to the x-values rather than the y-values.
What do students often miss when graphing transformations involving reflections?
Confusing the reflection across the x-axis (affects y-values) with the reflection across the y-axis (affects x-values).