How to Use the CASIO FX-115MS For the EIT Prepared by Test Masters Educational Services We have compiled some important functions that are needed for the EIT, and have shown below how to perform them on your calculator. However, we strongly recommend testing out all these functions using your calculator before the actual exam to ensure you know how to enter the data into your calculator correctly and verify the correct answer is given. This document was compiled only to assist you in learning your calculator while preparing for the EIT/FE exam. Test Masters takes no responsibility on how the calculator is used on the exam. Please send any feedback to calculator@testmasters.com 1. To Reset Mode , PRESS 1 2. Solving 2nd or 3rd Degree Polynomials Steps to find the roots to a polynomial. 1. 2. 3. 4. 5. 6. 7. 8. 9. Press Mode 3 times Æ Press 1 for EQN. Press the right arrow to go to Degrees. You do NOT want Unknowns. Press 2 for 2nd degree polynomial. Enter the value for a (the coefficient of x2). Press =. Enter the value for b (the coefficient of x). Press =. Enter the value for c (the constant). Press =. The first root is displayed. Hit the down arrow to see the second root. If the roots are complex (in the form of a ± bi ), you will see R ↔ I at the top right. If you see this, the first value given is the value of a. To display the value for b, press Shift, and then press =. Examples: 1. Solve t 2 − 8t + 3 = 0 Æ Answer: 7.6, 0.4 2. Solve x 2 − 4 x + 5 = 0 Æ Answer: 2 ± i See Calculation Instructions Below. Prepared By Test Masters Educational Services 3. Statistics Get into SD mode by pressing Mode 2 times, and then entering 1. SD will be displayed at the top. Once in SD mode, follow the calculator instructions below. • • • • Always clear the memory by pressing (Shift, Clr (Mode), 1, =) Enter each number, and then press the M+ Key after each one. Then press Shift, and then S-Var to find standard deviation or mean. Or press Shift, and then S-Sum to find the sum of the values or square of the values. See below. σ n = population standard deviation and σ n −1 = sample standard deviation • For Variance, square the standard deviation. Prepared By Test Masters Educational Services 4. Linear Regression Get into REG mode by pressing Mode 2 times, and then entering 2. REG will be displayed at the top. • • • • • Press 1 for Linear Regression. Enter the x-value, press the , (comma) key, and then the y-value. Press the M+ Key after entering each pair. Then press Shift, S-Var, and the right arrow twice. a = y-intercept, b = slope, r = correlation coefficient Press = to display the value. See calculator instructions below. Prepared By Test Masters Educational Services Prepared By Test Masters Educational Services 5. Polar –Rectangular Calculation 6. Base Conversion Get into BASE mode by pressing Mode 2 times, and then entering 3. So, Press 3 Once in BASE mode, you will see one of the following on the right side of the display: o, d, h, b Prepared By Test Masters Educational Services You can get into any of the four bases by pressing the buttons below. Notice how the letter on the right side changes as you change bases. h = hexadecimal (^ key) d = decimal (x2 key) o = octal (ln key) b = binary (log key) Steps for base conversion: 1. Get into the base mode, and then go to the base you would like to start with (o, d, b, h). 2. Enter the number. 3. Press =. Always remember to press = to set this number into the base. 4. Press the base key you would like to convert the number to (^, ln, log, . 5. Press Mode, 1 to get out of the base mode. 7. Permutations and Combinations Example: Combinations of People. A company employing 14 women and 10men is forming a six-person safety committee. How many different combinations of people are possible? 24 nCr 6 = Note: nCr is above the division key. ANSWER: 134, 596 Permutations of People: 24 nPr 6 = Note: nCr is above the multiplication key. ANSWER: 96,909,120 8. Integration Solve ∫ 1 −2 2 − x2 − x Æ Answer: 4.5 Prepared By Test Masters Educational Services Press the following keys separated by an arrow: ∫ dx → 2 → − → Alpha → X which is the ")" key → x 2 → − Alpha → X - which is the ")" key → , → − 2→ , → 1 → ) → = Prepared By Test Masters Educational Services Casio 115 • Casio 115 o Complex numbers. Put in Complex mode  Mode 2 o R – P (for ES only)  Shift 2 3 o P – R (for ES only)  Shift 2 4 o Rect Entry  Real + Imag(i) o Pol Entry  Real [Shift][(-)] angle o S=D button shift the calculator out of weird modes  “Symbolic – Decimal” o Shift Setup to change between Degrees, Radians, Grads • For 115MS o To shift from real to imaginary, use [shift][Re-Im] o P-R  Shift [-] o R-P  Shift [+]