Desmos Calculator Mastery • Lesson 3 of 7

Tables & Evaluating

Read a function at exact values without re-doing the arithmetic each time.

Often you need a function’s value at specific inputs — f(2), f(5), f(9). On the SAT’s Desmos you can add a table and type the x-values; a column like y_1 = 2x_1 + 1 fills in the outputs automatically. It is a private answer-checking machine: plug each multiple-choice value in and see which one hits the target.

In Vidaara’s calculator you get the same result from the Scientific tab: type the expression with the value substituted and read the answer. To test whether x = 4 satisfies 3x - 1 = 11, just compute 3*4 - 1 and check it equals 11.

  1. Open the Scientific tab.An entry line and a keypad appear.
  2. Type 3*4 - 1 and press =.It shows 11 — so x = 4 works.
  3. Re-type with the next candidate to test it.You confirm or rule out each answer choice in seconds.
💡
When a multiple-choice question gives four possible values, evaluating each one is often faster than solving the equation from scratch.
Try it liveEvaluate values on the Scientific tab
  • The Scientific calculator is below.
  • Type 3*4 - 1 and press = to test x = 4 in 3x - 1 = 11.
  • Try 2^5, sqrt(144), or (17/24)+(5/8).
← Graph Plotting Sliders →