Given that, r_1=2i-2j+k, r_2=-2i+2j-k and r_3=i+j+k, find a unit vector parallel to r_1+r_2+r_3

What is [tex] {7}^{98 + \sqrt{4} } - 3 \times (64 \div 2 + 4 - 36) \times a = a + 36[/tex]?

Atriangle has a side lengths of 18cm, 80 cm and 81cm. classify it as acute obtuse or right?

Scores on the cognitive scale of the bayley-scales of infant and toddler development range from 1 to 19, with a standard deviation of 3. calculate the margin of error in estimating the true mean cognitive scale score, with 99% confidence, if there are 12 infants and toddlers in a sample.