Avector a is added to b=6 i – 8 j . the resultant vector is in the positive x direction and has a magnitude equal to a. calculate the direction of a.

By adding B=6i-8i the restaurant then becomes (x+6)i + (y-8)j

The restaurant is in positive x direction which gives y=8

The magnitude of A and the restaurant are the same
x^2+y^2=(x+6)^2

12x=y^2-36=(8)^2-36=28
This gives x=7/3

Therefore vector A=(7/3) i +8j
The magnitude of A=sqrt [(7/3)^2+(8)^2]=25/3

A makes with positive x direction angle tan^(-1)
[8/(7/3)]
= tan^(-1) (24/7)

Hope this helps! :3

Neptune is the eighth planet from the sun. it was the first planet to get its existence predicted by  mathematical calculations  before it was actually seen through a telescope on sept. 23, 1846. irregularities in the orbit of  uranus  led french astronomer alexis bouvard to suggest that the gravitational pull from another celestial body might be responsible. german astronomer johann galle then relied on subsequent calculations to   spot neptune via telescope. previously, astronomer galileo galilei sketched the planet, but he mistook it for a star due to its slow motion. in accordance with all the other planets seen in the sky, this new world was given a name from greek and roman mythology — neptune, the roman god of the sea.

It is d, all the other ones say incorrect answer .