Answer:
A ≈ 119.7°, b ≈ 25.7, C ≈ 24.3°
Step-by-step explanation:
A suitable app or calculator does this easily. (Since you're asking here, you're obviously not unwilling to use technology to help.)
_____
Given two sides and the included angle, the Law of Cosines can help you find the third side.
... b² = a² + c² - 2ac·cos(B)
... b² = 38² + 18² -2·38·18·cos(36°) ≈ 661.26475
... b ≈ 25.715
Then the Law of Sines can help you find the other angles. It can work well to find the smaller angle first (the one opposite the shortest side). That way, you can tell if the larger angle is obtuse or acute.
... sin(C)/c = sin(B)/b
... C = arcsin(c/b·sin(B)) ≈ 24.29515°
This angle and angle B add to less than 90°, so the remaining angle is obtuse. (∠A can also be found as 180° - ∠B - ∠C.)
... A = arcsin(a/b·sin(B)) ≈ 119.70485°
Your first choice is the correct answer and I am 100% sure.
*Quack* 7 hope this helps fellow duck!
Answer:
a) True
b) False
c) False
d) False
e) True
Step-by-step explanation:
a) Each basis of V has four vectors. Then any set of 5 vectors must be linear dependent (LD).
b) Suppose that
is a basis of V. Considere the set
where
are scalars. The set has 5 vectors but
because
is not belong to A and
is linear independent of
c) Suppose that
is a basis of V. Considere the set
where
are scalars. A has four nonzero vectors but isn't a basis because is a LD set.
d) Suppose that
is a basis of V. Considere the set
where
are scalars. A has 3 nonzero vectors but isn't a basis because is a LD set.
e) Since any basis of V must have 4 elements, then a set of three vectors cannot generate V.