Question

if 0.5i^+0.8j^+ck^ is a unit vector , then the value of c is

Answer 1

Magntude of unit vector is 1

Magnitude of 0.5i + 0.8j + ck should also be equal to 1

So,

1 = √(0.5² + 0.8² + c²)
1 = 0.25 + 0.64 + c²
c² = 1 - 0.89
c = √0.11

Value of c should be √0.11

Answer 2

Answer:

|a+b+c|=1

√0.5²+0.8²+c²=1

squaring both sides  

0.5²+0.8²+c²=1

0.25+0.64+c²=1

c²+0.89=1.00

c²=0.11

c=√0.11