The coordinates of three points are A(-1,-3), B (2,3) and C(6,k) If AB is perpendicular to BC then find a) The value of k
b) the gradient of AC
c) the acute angle that AC makes with the x-axis.
My answer for (b) is 4/7 but the actual answer is 4/5. And I have problems with (c) too. Kindly please show your working. Thank you very much.

ha!

i just did this!

18. g

20. h 30 degree turn.

21. d 90 degree angles

and also 19 is a. a sphere not a cirlcle

hope i !

pls mark me brainiest

step-by-step explanation:

if you want to solve percent error follow these steps.

1. subtract the accepted value from the experimental value.

2. take the absolute value of step 1.

3. divide that answer by the accepted value.

4. multiply that answer by 100 and add the % symbol to express the answer as a percentage.

if you want to solve percent of change just do this.

1. work out the difference (increase) between the two numbers you are comparing.

2. divide the increase by the original number and multiply the answer by 100. if your answer is a negative number then this is a percentage decrease.

hope this : )

option (b) is correct

step-by-step explanation:

to find the solution of this system, we need to convert it into reduced row-echelon form. we have,

after applying row operations r2 -> r2/2 and r3 -> r3/3, we get,