Answer:
See the argument below
Step-by-step explanation:
I will give the argument in symbolic form, using rules of inference.
First, let's conclude c.
(1)⇒a by simplification of conjunction
a⇒¬(¬a) by double negation
¬(¬a)∧(2)⇒¬(¬c) by Modus tollens
¬(¬c)⇒c by double negation
Now, the premise (5) is equivalent to ¬d∧¬h which is one of De Morgan's laws. From simplification, we conclude ¬h. We also concluded c before, then by adjunction, we conclude c∧¬h.
An alternative approach to De Morgan's law is the following:
By contradiction proof, assume h is true.
h⇒d∨h by addition
(5)∧(d∨h)⇒¬(d∨h)∧(d∨h), a contradiction. Hence we conclude ¬h.
Answer:
B
Step-by-step explanation:
Using the exact values
cos150° = - cos30° = - 
sin150° = sin30° = 
Given
z = 4(cos150° + isin150° ) , substitute values
= 4(-
+
i )
= - 2
+ 2i , that is
(- 2
, 2 ) → B
Answer:
26
Step-by-step explanation:
Convert 40% to a decimal
40% = 0.4
Multiply 0.4 with 65
0.4 • 65 = 26
40% of 65 is 26
Answer:
The answer is 25
Step-by-step explanation: