In the circle, O is the centre and AB is a diameter. a) work out the size of angle a

b) work out the size of angle b

Step-by-step explanation:

a). m∠a = 62°

b). m∠b = 118°

Step-by-step explanation:

a). Since, an angle inscribed in a semicircle is a right angle,

  m∠ACB = 90°

  By triangle sum theorem in ΔABC,

  m∠CAB + m∠ACB + m∠ABC = 180°

  28° + 90° + m∠ABC = 180°

  118° + m∠ABC = 180°

  m∠ABC = 180°- 118°

  a = 62°

b). Since, quadrilateral ABCD is a cyclic quadrilateral,

   m∠ADC + m∠ABC = 180°

   b + a = 180°

   b + 62° = 180°

   b = 180° - 62°

   b = 118°

the answer for this question is 38

x =±sqrt(1/3)

step-by-step explanation:

x+4/6x=1/x

multiply each side by 6x to get rid of the fractions

6x*(x+4/6x)=1/x*6x

distribute

6x^2 +4 = 6

subtract 4 from each side

6x^2 +4-4 = 6-4

6x^2 =2

divide by 6

6x^2/6 = 2/6

x^2 = 1/3

take the square root of each side

sqrt(x^2) = ±sqrt(1/3)

x =±sqrt(1/3)