Test 3 (proofs, trig) Flashcards
implication
if A then B; A only if B
what is converse of if Q then P?
if P then Q
how to prove equivalence?
prove implication in both directions
what is enough with ‘there exists’ statements?
just one example
What is the concluding sentence of induction?
Because the IH holds for n = nekaj and if it holds for some n, it also holds for n +1, threfore it holds for all n E N
What are the sides of an angle called
the terminal & initial side
what are coterminal angles
angles with same initial & terminal side
what is 1 radian?
the angle in standard position that is subtended by an arc of length 1 on the unit circle
when is a function periodic?
if we have a period A, so it holds f(x + A) = f(x)
at what angle does sine go through the origin
45 degrees
how is sinusoidal function period calculated?
period = 2pi / B
what is 1 + tan**2 equal to?
1 / cos**2
what is 1 + cot**2 equal to?
1 / sin**2
what is the cos of the sum of two angles?
the difference of the products of the cosines and sines of these angles
what is the sin of the sum of two angles?
sin a * cos b + cos a * sin b
