We have to find t(theta) in radians.
cos t = cos 65° + cos 55°
We know that:
cos x + cos y = 2 · cos (x+y)/2 · cos (x - y)/2
cos t = 2 · cos (65°+55°)/2 · cos (65°-55°)/2
cos t = 2 · cos 60°· cos 5°
cos t = 2 · 1/2 · cos 5°
cos t = cos 5°
t = 5° = π/36 radians
To find the average assessment, add the 5 grades together, then divide by the quantity of grades added together (in this case 5).
=56 + 42 + 47 + 59 + 48
=252
=252 ÷ 5
=50.4 average
ANSWER: Yes, he passes his course with an average grade of 50.4.
Hope this helps! :)
$300 income
$250 + $100 = $350 expenses
$300 - $350 = a loss of $50