Yes that is what I was doing Chris, I just didn't halve them because I wanted to do it in my head. :))
Here is another way Sweaty, although it is probably over your head.
You can use calculus and get a lot of accuracy very quickly using
Newton's method of approximating roots.
I derive this formula every time I use it for a have a really bad memory but most people just memorise the formula.
x2=x1−f(x1)f′(x1)
letx=√6x2=6x2−6=0$theideaistolet$f(x)=x2−6$andsolvefor$y=0f(x)=x2−6f′(x)=2x$thatiscalculus$$nowweknowthat$2$Somyfirstestimatewillbe$x1=2.5x2=2.5−2.52−62∗2.5x2=2.45
\\\mbox{second use of the formula}\\\\ x_3=2.45-\frac{2.45^2-6}{2*2.45}\\\\ x_3=\textcolor[rgb]{1,0,0}{\mathbf{2.449489796}}\\\\ $third use of the formula$\\\\ x_4=2.449489796-\frac{2.449489796^2-6}{2*2.449489796}\\\\ x_4=\textcolor[rgb]{1,0,0}{\mathbf{2.449510072}}\\\\ $The value is already correct to 4 decimal places } \sqrt{6}=2.4495\\\\\\ $With each iteration the accuracy will increase.$
You will learn and understand this when you do calculus - something to look forward too :))
Well there would be a number of ways Sweatie. The easiest one is to use a calculator.
This is another way:
You know it is between 2 and 3
2<√6<3
2.52=6.25$thatistoobig$2<√6<2.52.32=5.29$toosmall$2.3<√6<2.52.42=5.76$toosmall$2.4<√6<2.5etc
you can continue to do this untill you get the accuracy that you need.
Note: I did not use a calculator at all for what I have done so far there.
This is an incite into how I do it. :)
232=(20+3)2=400+2∗3∗20+9=400+120+9=529so2.32=5.29$Icandothatinmyhead−withpracticeyoucouldtoo.:)$
Here is a method that is similar to Melody's...it converges pretty fast....even if our intial guess is not too good.
This method is known as "Guess - Divide - Check "
Step 1 : Let's say that we guess the square root of 6 as 2
Step 2 : Divide 6 by 2 = 3
Step 3 : Now add 2 +3 and divide by 2 = 2.5
Step 4: Now divide 6 by 2.5 = 2.4
Step 5: Now add 2.5 and 2.4 and divide by 2 = 2.45
Step 6 : Divide 6 by 2.45 = 2.448
Step 7 : Add 2.448 and 2.45 and divide by 2 = 2.449
Step 8: Divide 6 by 2.449 = 2.449......note this is pretty close to the actual square root of 6 !!!
This isn't hard to do.....once you get the "rhythm" down.....!!!!......with a better initial guess.....the procedure may have even converged much more quickly!!!
P.S. - The method might be better termed as "Guess - Divide - Average - Divide - Average - Divide......."
Yes that is what I was doing Chris, I just didn't halve them because I wanted to do it in my head. :))
Here is another way Sweaty, although it is probably over your head.
You can use calculus and get a lot of accuracy very quickly using
Newton's method of approximating roots.
I derive this formula every time I use it for a have a really bad memory but most people just memorise the formula.
x2=x1−f(x1)f′(x1)
letx=√6x2=6x2−6=0$theideaistolet$f(x)=x2−6$andsolvefor$y=0f(x)=x2−6f′(x)=2x$thatiscalculus$$nowweknowthat$2$Somyfirstestimatewillbe$x1=2.5x2=2.5−2.52−62∗2.5x2=2.45
\\\mbox{second use of the formula}\\\\ x_3=2.45-\frac{2.45^2-6}{2*2.45}\\\\ x_3=\textcolor[rgb]{1,0,0}{\mathbf{2.449489796}}\\\\ $third use of the formula$\\\\ x_4=2.449489796-\frac{2.449489796^2-6}{2*2.449489796}\\\\ x_4=\textcolor[rgb]{1,0,0}{\mathbf{2.449510072}}\\\\ $The value is already correct to 4 decimal places } \sqrt{6}=2.4495\\\\\\ $With each iteration the accuracy will increase.$
You will learn and understand this when you do calculus - something to look forward too :))