setRoot from Tab1 to Tab2

In Ionic 3…
i am having 2 Tabs

Tab1 contains 4 pages
Tab2 Contains 5 pages…

i am setRoot from Tab1 to Tab2 … i am getting Tab2 is active but Tab1 pages also Exists here & there are also displaying

How to setRoot completely from Tab1 to Tab2 without strucking the pages ???