Our substitution feature allows you to answer the question "What would be the value of this expression if we substituted a different value for A?," without ever changing the original value of A.
Using the ‘with’ substitution function, you can replace a variable in an expression with a constant value, another variable expression, or a list.
You can find this function in the “Advanced” section of the “Functions” menu on the keypad, or ‘with’ can also be typed directly into an expression line using your keyboard.
Substitution within a Function
Where would the parabola \(f\left(x\right)=ax^{2}+bx+c\) move if \(b\) were \(-1\)? Model \(f\left(x\right)\) after substituting \(b\) with \(-1\) to visualize the change.
Next, trying graphing the vertex of the original function \((V)\) and using substitution to also graph the vertex when \(b = -1\).
Substitution within the Same Expression Line
You can evaluate expressions by substituting variables with constant values in the same line. You can also substitute a variable with another expression, but if that expression depends on a free variable, it will need to be defined separately.