Answer:
False, counterexample below
Step-by-step explanation:
Denote the unit vectors of R^3 by . Now consider
and
. We have that
. Also, the vector
is not a linear combination of
because any linear combination of these two vectors will have third coordinate zero, but v_3 has third coordinate 1 so they can't be equal.
However, the set is not linearly independent, because
is a non-trivial linear combination of these vectors that equals zero.
Answer:
see explanation
Step-by-step explanation:
Given A is directly proportional to r² then the equation relating them is
A = kr² ← k is the constant of proportion
To find k use the condition when r = 5, A = 75 , then
75 = k × 5² = 25k ( divide both sides by 25 )
3 = k
A = 3r² ← equation of proportion
(a)
when r = 4, then
A = 3 × 4² = 3 × 16 = 48
(b)
when A = 147 , then
147 = 3r² ( divide both sides by 3 )
49 = r² ( take the square root of both sides )
r = = 7