HP 39GS hp 39gs_user's guide_English_E_HDPMG39AE13.pdf - Page 155

! For a description, see "COMB(5,2) returns 10. That is, there are ten different ways that five things can be combined two at a time.!" on page 13-12. ∑ For a description, see "Σ" on page 13-11. EEX For a description, see "Scientific notation (powers of 10)" on page 1-20. ∫ For a description, see " ∫ " on page 11-7. x-1 The multiplicative inverse function finds the inverse of a square matrix, and the multiplicative inverse of a real or complex number. Also works on a list containing only these object types. Keyboard functions The most frequently used functions are available directly from the keyboard. Many of the keyboard functions also accept complex numbers as arguments. ,, , ex Add, Subtract, Multiply, Divide. Also accepts complex numbers, lists and matrices. value1+ value2, etc. Natural exponential. Also accepts complex numbers. e^value Example e^5 returns 148.413159103 Natural logarithm. Also accepts complex numbers. LN(value) Example LN(1) returns 0 Using mathematical functions 13-3