CH21 A B C D For the expression that follows replace x with

CH2.1

A)

B)

C)

D)

For the expression that follows, replace x with 45 and then simplify as much as possible. 8 cos (2x 450)

Solution

A)cos(2x-45^o),x=45^o

cos(2(45^o) -45^o)

=cos(90^o-45^o)

=cos(45^o)

=1/2

B)(38^o42\')+(24^o23\')

=(38+24)^o(42+23)\'

=(62)^o(65)\'

=(62+1)^o05\'

=63^o05\'

C)(90^o)-(25^o29\')

=(89^o60\')-(25^o29\')

=(89-25)^o+(60-29)\'

=64^o31\'

D)(84^o33\')-(26^o56\')

=(83^o(60+33)\')-(26^o56\')

=(83-26)^o(60+33-56)\'

=57^o37\'