How do you multiply two float numbers without using multipliers?

[Marcee]

How do you multiply two float numbers without using multipliers?

The chips can be any.

let a = 0.1;
let b = 0.2;

[emerson]

Modalities

1. use of separation

    const res = a / (1 / b);
   

Method universal in comparison with method (2), NEDROSTAT - if b = 0That way doesn't work.

2. using logarithms and exhibitors

    const res = Math.exp(Math.log(a) + Math.log(b))
   

2.1. Same as 2, but the degree and logarithm on the basis of 10 may be used:

    const res = Math.pow(10, Math.log10(a) + Math.log10(b))

2.2. Same as 2, but the degree and logarithm on the basis of 2:

    const res = Math.pow(2, Math.log2(a) + Math.log2(b))

There's a lot of options for logarithms, because you can use logarithms with arbitrary grounds.

But there's a NEDROSTAT - it's impossible to work with negative numbers and zero.

3. Use tangenes:

any number can be imagined as a thangens angle a = tan(x)so we can use the trigonometric tone:

tan(x + y) = (tan(x) + tan(y)) / (1 - tan(x)*tan(y))

in this way

1 - (a + b) / (tan(atan(a) + atan(b)) = a * b

I mean.

res = 1 - (a + b) / (Math.tan(Math.atan(a) + Math.atan(b))

NEXT: An option where tan(atan(a) + atan(b) = 0 Again, because the functions are counted through the rows, the accuracy (almost)