20 Most Recent Texas Instruments TI-30XA Calculator - Page 7 Questions & Answers

Unfortunately this calculator does not display results in radical form. If you enter SQRT(147) you get 12.12435565... What you are asking for is called rationalizing an irrational expression. Usually one tries to get rid of radicals that appear in the denominators. Here is an example. Suppose you have 1/(c+SQRT(d)), and you want to get rid of the radical in the denominator. How to do it? Recall the identity (a-b)*(a+b)= a^2-b^2. It is true for any a and b Rationalizing a denominator (usual case) Now consider (c+SQRT(d)). Multiply it by (c-SQRT(d)) [c+SQRT(d)]*[c-SQRT(d)]=c^2 -[SQRT(d)]^2=c^2-d You see that there is no radical. Now take 1/(c+SQRT(d)). To get rid of the radical from the denominator multiply it by (c-SQRT(d)). But to leave the value of your expression 1/(c+SQRT(d)) unchanged, you must multiply both numerator and denominator by (c-SQRT(d)). The numerator becomes 1*(c-SQRT(d))=c-SQRT(d), and the denominator (c^2-d). Finally, the rationalized form of the expression 1/(c+SQRT(d)) is [c-SQRT(d)]/[c^2-d]. Rationalizing a numerator Sometimes, people have a radical in the numerator that they want to get rid of and have it in the denominator. The procedure is the same Example:(c+SQRT(d)), the denominator here is 1 (c+SQRT(d))=(c+SQRT(d))*[c-SQRT(d)]/[c-SQRT(d)]. This gives [c^2-d]/[c-SQRT(d)] You have no radical in the numerator but there is one in the denominator. This is called rationalizing the numerator. Your case is a lot simpler SQRT(147)=7*SQRT(3) Multiply it by SQRT(3)/SQRT(3) which is 1. This gives SQRT(147)=7*3/SQRT(3)=21/SQRT(3) SQRT(147)= 21/SQRT(3)

2 to the 10th power

There isn't a rounding key as such. However you can control the number of digits displayed. See page 16 of the manual: http://www.fixya.com/support/p131668-texas_instruments_ti_30xa_calculator/manual-5027

For ln use the LN key on the top row of the keyboard. For e^x use the 2nd function of the LN key.

You may view and/or download the manual at http://www.fixya.com/support/p3854515-texas_instruments_ti_30xa_scientific_cal/usermanual-77551D8-pdf

This calculator does not have a key that you can use to find the prime factor of an integer. You can however use the calculator to find the factors 1. If number is even divide it by 2 Keep dividing by 2, while keeping track of how many times you divided by 2. If you divided 5 times by 2 before getting an odd number, then your first factor is 2^5 2. Now try dividing by 3, keep track of the number of times you divided by 3 before you could not divide by 3 any more. If you divided 0 times by 3, your second factor is 3^0, or 1 and 3 is not a factor. If you divided 4 times by 3, your second factor is 3^4 3. Divide by 5, until you can't any more. Keep track of the number of times you divided by 5. 4. Divide by all other prime numbers 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, etc. For each prime number, keep track of how many times you divided by it, until you could not any more. Example: 23100 Division by 2 23100/2=11550 ---------> 1 division by 2 11550/2=5775 ----------> 2 divisions by 2 Note that 5775 is not divisible by 2. No more divisions by 2. First factor is 2^2 Division by 3: 5775/3=1925 ----------> 1 division by 3 1925/3=641. 66667 Not an integer. No more divisions by 3. 2nd factor is 3^1 Division by 5 (number ends in 5) 1925/5 =385 -------> 1 division by 5 385/5=77 ----------> 2 divisions by 5 and no more (quotient does not end in 0 or 5) 3rd factor is 5^2 Division by 7 77/7=11 --------> 1 division by 7, and no more 4th factor is 7^1=7 Division by 11 11/11=1 5th factor is 11^1=11 Assembling the factors 2^2, 3^1, 5^2, 7, 11 Prime factorization of 23100 is 23100=(2^2)(3)(5^2)(7)11

On the 30Xa, press the DRG key to cycle through the different angular modes. Be aware that no matter what mode you set, the display will show an indicator of the current mode. You can't remove the indicator completely.

Use the general power key marked [X^y] or [Y^x] or just [^]

You don't. If you want to input an angle in degrees-minutes-seconds, simply enter it as DD.MMSS . See page 7 of the manual: http://www.fixya.com/support/p131668-texas_instruments_ti_30xa_calculator/manual-5027

The 30XA only calculates logs to base e (LN) and base 10 (LOG). However you can calculate the log of x to any base b simply by calculating log(x)/log(b) or ln(x)/ln(b)

Press 5 0 0 EE 3 to get 500,000.

Almost exactly as you typed it: 9 + ( 8 +/- 4 ) y^x 2 = +/- is just to the right of the decimal point, y^x is just above the divide.

Almost exactly as you typed it: 9 + ( 8 +/- 4 ) y^x 2 = +/- is just to the right of the decimal point, y^x is just above the divide.

use you warranty.

There is no unknown variable to solve for. This is just a numerical calculation which you can let your calculator do. If the terms 5 ln 8 and -ln9 are in the same denominator enclose the denominator between parentheses.