Simple Sec 1 question

1) find the smallest positive interger m for which square root of 240 m is a whole number

Ans: m = 15

working and why ???

are you sec1?

break down into prime factors.

sq numbers have even power.

short of 3×5=15

explaination indeed is m=3x5=15...

but I abit catch no ball...

break down into prime factors.

sq numbers have even power.

short of 3×5=15

ehhh... okay... so meaning take out the even prime numbers...???

explaination indeed is m=3x5=15...

but I abit catch no ball...

*throws a rubber ball to xiao xiao*

240 = 2power4×3 x 5

3 and 5 need to make into 3power2 n 5power2

m = 3×5

240 = 2power4×3 x 5

3 and 5 need to make into 3power2 n 5power2

m = 3×5

OHHHHH okay... Got it...

Understood le...

hokay... another similiar question...

in the event of cube instead of square, do I find the power to the nearest odd number or multiple of 3??

Edited: Hokay, I did some test... so cuberoot need power to be multiple of 3 instead of nearest odd number...

thanks fifi for answering my question...

hokay... another similiar question...

in the event of cube instead of square, do I find the power to the nearest odd number or multiple of 3??

Edited: Hokay, I did some test... so cuberoot need power to be multiple of 3 instead of nearest odd number...

thanks fifi for answering my question...

I like your attitude very much, you are right and I believe you will be able to extend your result to 4th root etc...

Keep it up, you will not have any problem with your maths.

Here is another similar example that you may want to try out: find the smallest positive integer m such that 210m / 72 is a whole number.