A)16 B)18 C)20 D)22 E)24
A= 13+26+39+...+169=
= 13(1+2+3+....+13)=
=13* (13*14)/2=
=13*13*7
=> 13+7=20
So the answer is c)
{a,e,i, o}
Answer: π/6
Step-by-step explanation:
sec θ =
sec =
⇒ =
⇒ cos θ =
Since it is an acute angle, then 0° > θ > 90°
Look at the Unit Circle to find that cos θ = at π/6
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Answer: -300°
Step-by-step explanation:
Set up the proportion:
Cross multiply and solve:
π(3x) = 180(-5π)
x =
x = 60(-5)
x = -300