Answer:
The dot product of (7,5) and (-5,4) is -15
Step-by-step explanation:
Given
(7,5) and (-5,4)
Required
Determine the dot product
Dot product is calculated using the following formula;

Let a = (7,5) and b = (-5,4);
The above formula becomes



Hence, the dot product of (7,5) and (-5,4) is -15
X/15 = 10/20
20x = 150
x = 150/20
x = 7.5
Answer:
Therefore the rate of growth of the tree is 33 cm/ yr.
Step-by-step explanation:
Given that,
The height of the tree is
H= 210 +33t
Here H represent the height of tree in cm and t is time in year.
The rate of growth is the first order derivative of the H with respect to time.
i.e The rate of growth 
∴H= 210 +33t
Differentiating with respect to t


Therefore the rate of growth of the tree is 33 cm/ yr.
Answer: 7(sin 50 degrees)
Step-by-step explanation: