Question

Question #d62c9

Answer 1

`b=+-sqrt15`

Explanation:

`" the magnitude of " <2,6>" is"`

`sqrt(2^2+6^2)=sqrt40`

`"require " <-5,b>" to have the same magnitude"`

`rArrsqrt((-5)^2+b^2)=sqrt40`

`rArrsqrt(25+b^2)=sqrt40`

`color(blue)" square both sides"`

`rArr25+b^2=40tob^2=15`

`rArrb=+-sqrt15`