1 + tan ² Ф=sec²Ф
1+(12/5)²=sec²Ф
169/25=sec² Ф
sec Ф=⁺₋√(169/25)=⁺₋13/5
sec Ф=1/cos Ф ⇒cosФ=1/sec Ф
cos Ф>0 ⇔ sec Ф>0 ⇔ sec Ф=+ 13/5
cos Ф=1/secФ
cos Ф=1 / 13/5=5/13
we can calculate the sin Ф, with this method.
sin²Ф + cos²Ф=1 ⇒ sin Ф=⁺₋√(1-cos² Ф)
sin Ф=⁺₋√[1-(5/13)²]=⁺₋12/13
like cos Ф>0 and tan Ф>0 ⇒ sin Ф>0 ⇒sin Ф=12/13
answer: d.12/13
other method
tan Ф=sin Ф / cos Ф
12/5=sin Ф / 5/13
sin Ф=(12/5)*(5/13)=12/13
answer: d.12/13
WANR: 22%
WWCN: 41%
WCLM: 24%
WKOD: 13%
However is B. WWCN.
Answer:
Raul's errors are in the application of the distributive property(he applied it wrongly), in not respecting the precedence of operations, and in the multiplication of two terms with the same base(we add the exponent).
Step-by-step explanation:
Distributive property:
The distributive property of multiplication is:
a*(b + c) = a*b + a*c
Precedence of operations:
First multiplication, then addition.
Multiplication of terms with the same base:
The multiplication of h*h = h², which Raul missed.
The correct simplification is given by: