Question

Help Please !!!1
number 13

Answer 1

@mathmale

Answer 2

@mathmale

Answer 3

thus \(\bf r^2=x^2+y^2\implies r^2=x^2+1^2\implies r^2-1=x^2
\\ \quad \\
\cfrac{d}{dt}[r^2-1]=\cfrac{d}{dt}[x^2]\)

Answer 4

and they pythagorean theorem applies, because is a right triangle

Answer 5

the pythagorean theorem rather